diff --git a/.gitignore b/.gitignore
index c4e15e9d..b16e3d0b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@
 *.out
 *.toc
 *.synctex.gz
+**/model_data
\ No newline at end of file
diff --git a/README.md b/README.md
index f70a2d87..2141c480 100644
--- a/README.md
+++ b/README.md
@@ -216,7 +216,7 @@ If I forgot to add you, please let me know!
 
 [Github issues]:         https://github.com/VLSIDA/PrivateRAM/issues
 [Github pull request]:   https://github.com/VLSIDA/PrivateRAM/pulls
-[Github projects]:       https://github.com/VLSIDA/PrivateRAM/projects
+[Github projects]:       https://github.com/VLSIDA/PrivateRAM
 
 [email me]:              mailto:mrg+openram@ucsc.edu
 [dev-group]:             mailto:openram-dev-group@ucsc.edu
diff --git a/compiler/characterizer/__init__.py b/compiler/characterizer/__init__.py
index 19da7d59..fc42a889 100644
--- a/compiler/characterizer/__init__.py
+++ b/compiler/characterizer/__init__.py
@@ -9,6 +9,8 @@ from .functional import *
 from .worst_case import *
 from .simulation import *
 from .bitline_delay import *
+from .measurements import *
+from .model_check import *
 
 debug.info(1,"Initializing characterizer...")
 OPTS.spice_exe = ""
diff --git a/compiler/characterizer/bitline_delay.py b/compiler/characterizer/bitline_delay.py
index e5a50c16..c85f06bc 100644
--- a/compiler/characterizer/bitline_delay.py
+++ b/compiler/characterizer/bitline_delay.py
@@ -22,11 +22,24 @@ class bitline_delay(delay):
         self.period = tech.spice["feasible_period"]
         self.is_bitline_measure = True
     
+    def create_signal_names(self):
+        delay.create_signal_names(self)
+        self.bl_signal_names = ["Xsram.Xbank0.bl", "Xsram.Xbank0.br"]
+        self.sen_name = "Xsram.s_en"
+
     def create_measurement_names(self):
         """Create measurement names. The names themselves currently define the type of measurement"""
         #Altering the names will crash the characterizer. TODO: object orientated approach to the measurements.
-        self.bitline_meas_names = ["bl_volt", "br_volt"]
+        self.bl_volt_meas_names = ["volt_bl", "volt_br"]
+        self.bl_delay_meas_names = ["delay_bl", "delay_br"] #only used in SPICE simulation
+        self.bl_delay_result_name = "delay_bl_vth" #Used in the return value
     
+    def set_probe(self,probe_address, probe_data):
+        """ Probe address and data can be set separately to utilize other
+        functions in this characterizer besides analyze."""
+        delay.set_probe(self,probe_address, probe_data)
+        self.bitline_column = self.get_data_bit_column_number(probe_address, probe_data)
+        
     def write_delay_measures(self):
         """
         Write the measure statements to quantify the bitline voltage at sense amp enable 50%.
@@ -38,26 +51,52 @@ class bitline_delay(delay):
             self.sf.write("* {}\n".format(comment))
             
         for read_port in self.targ_read_ports:
-           self.write_bitline_measures_read_port(read_port)       
+           self.write_bitline_voltage_measures(read_port)       
+           self.write_bitline_delay_measures(read_port)
            
-    def write_bitline_measures_read_port(self, port):
+    def write_bitline_voltage_measures(self, port):
+        """
+        Add measurments to capture the bitline voltages at 50% Sense amp enable
+        """
+        debug.info(2, "Measuring bitline column={}, port={}".format(self.bitline_column,port))
+        if len(self.all_ports) == 1: #special naming case for single port sram bitlines
+            bitline_port = ""
+        else:
+            bitline_port = str(port)
+            
+        sen_port_name = "{}{}".format(self.sen_name,port)
+        for (measure_name, bl_signal_name) in zip(self.bl_volt_meas_names, self.bl_signal_names):
+            bl_port_name = "{}{}_{}".format(bl_signal_name, bitline_port, self.bitline_column)
+            measure_port_name = "{}{}".format(measure_name,port)
+            self.stim.gen_meas_find_voltage(measure_port_name, sen_port_name, bl_port_name, .5, "RISE", self.cycle_times[self.measure_cycles[port]["read0"]])
+    
+    def write_bitline_delay_measures(self, port):
         """
         Write the measure statements to quantify the delay and power results for a read port.
         """
         # add measure statements for delays/slews
-        measure_bitline = self.get_data_bit_column_number(self.probe_address, self.probe_data)
-        debug.info(2, "Measuring bitline column={}".format(measure_bitline))
-        for port in self.targ_read_ports:
-            if len(self.all_ports) == 1: #special naming case for single port sram bitlines
-                bitline_port = ""
-            else:
-                bitline_port = str(port)
-                
-            sen_name = "Xsram.s_en{}".format(port)
-            bl_name = "Xsram.Xbank0.bl{}_{}".format(bitline_port, measure_bitline)
-            br_name = "Xsram.Xbank0.br{}_{}".format(bitline_port, measure_bitline)
-            self.stim.gen_meas_find_voltage("bl_volt", sen_name, bl_name, .5, "RISE", self.cycle_times[self.measure_cycles[port]["read0"]])
-            self.stim.gen_meas_find_voltage("br_volt", sen_name, br_name, .5, "RISE", self.cycle_times[self.measure_cycles[port]["read0"]])
+        for (measure_name, bl_signal_name) in zip(self.bl_delay_meas_names, self.bl_signal_names):
+            meas_values = self.get_delay_meas_values(measure_name, bl_signal_name, port)
+            self.stim.gen_meas_delay(*meas_values)
+    
+    def get_delay_meas_values(self, delay_name, bitline_name, port):
+        """Get the values needed to generate a Spice measurement statement based on the name of the measurement."""
+        if len(self.all_ports) == 1: #special naming case for single port sram bitlines
+            bitline_port = ""
+        else:
+            bitline_port = str(port)
+        
+        meas_name="{0}{1}".format(delay_name, port)
+        targ_name = "{0}{1}_{2}".format(bitline_name,bitline_port,self.bitline_column)
+        half_vdd = 0.5 * self.vdd_voltage
+        trig_val = half_vdd
+        targ_val = self.vdd_voltage-tech.spice["v_threshold_typical"]
+        trig_name = "clk{0}".format(port)
+        trig_dir="FALL" 
+        targ_dir="FALL"
+        #Half period added to delay measurement to negative clock edge
+        trig_td = targ_td = self.cycle_times[self.measure_cycles[port]["read0"]]  + self.period/2
+        return (meas_name,trig_name,targ_name,trig_val,targ_val,trig_dir,targ_dir,trig_td,targ_td)
     
     def gen_test_cycles_one_port(self, read_port, write_port):
         """Sets a list of key time-points [ns] of the waveform (each rising edge)
@@ -89,6 +128,7 @@ class bitline_delay(delay):
         self.add_read("R data 0 address {} to check W0 worked".format(self.probe_address),
                       self.probe_address,data_zeros,read_port)
         self.measure_cycles[read_port]["read0"] = len(self.cycle_times)-1
+        
     def get_data_bit_column_number(self, probe_address, probe_data):
         """Calculates bitline column number of data bit under test using bit position and mux size"""
         if self.sram.col_addr_size>0:
@@ -115,19 +155,70 @@ class bitline_delay(delay):
         self.stim.run_sim() #running sim prodoces spice output file.
           
         for port in self.targ_read_ports:  
-            bitlines_meas_vals = {}
-            for mname in self.bitline_meas_names:
-                bitlines_meas_vals[mname] = parse_spice_list("timing", mname)
-            #Check that power parsing worked.
-            for name, val in bitlines_meas_vals.items():
-                if type(val)!=float:
-                    debug.error("Failed to Parse Bitline Values:\n\t\t{0}".format(bitlines_meas_vals),1) #Printing the entire dict looks bad.
-            result[port].update(bitlines_meas_vals)
+            #Parse and check the voltage measurements
+            bl_volt_meas_dict = {}  
+            for mname in self.bl_volt_meas_names:
+                mname_port = "{}{}".format(mname,port)
+                volt_meas_val = parse_spice_list("timing", mname_port)
+                if type(volt_meas_val)!=float:
+                    debug.error("Failed to Parse Bitline Voltage:\n\t\t{0}={1}".format(mname,volt_meas_val),1)
+                bl_volt_meas_dict[mname] = volt_meas_val
+            result[port].update(bl_volt_meas_dict)
+
+            #Parse and check the delay measurements. Intended that one measurement will fail, save the delay that did not fail.
+            bl_delay_meas_dict = {}
+            values_added = 0 #For error checking
+            for mname in self.bl_delay_meas_names: #Parse 
+                mname_port = "{}{}".format(mname,port)
+                delay_meas_val = parse_spice_list("timing", mname_port) 
+                if type(delay_meas_val)==float: #Only add if value is float, do not error.
+                    bl_delay_meas_dict[self.bl_delay_result_name] = delay_meas_val * 1e9 #convert to ns
+                    values_added+=1
+            debug.check(values_added>0, "Bitline delay measurements failed in SPICE simulation.")
+            debug.check(values_added<2, "Both bitlines experienced a Vth drop, check simulation results.")  
+            result[port].update(bl_delay_meas_dict)
         
-          
         # The delay is from the negative edge for our SRAM
         return (True,result)
     
+    def check_bitline_all_results(self, results):
+        """Checks the bitline values measured for each tested port"""
+        for port in self.targ_read_ports:
+            self.check_bitline_port_results(results[port])
+  
+    def check_bitline_port_results(self, port_results):
+        """Performs three different checks for the bitline values: functionality, bitline swing from vdd, and differential bit swing"""
+        bl_volt, br_volt = port_results["volt_bl"], port_results["volt_br"]
+        self.check_functionality(bl_volt,br_volt)
+        self.check_swing_from_vdd(bl_volt,br_volt)
+        self.check_differential_swing(bl_volt,br_volt)
+        
+    def check_functionality(self, bl_volt, br_volt):
+        """Checks whether the read failed or not. Measured values are hardcoded with the intention of reading a 0."""
+        if bl_volt > br_volt:
+            debug.error("Read failure. Value 1 was read instead of 0.",1)
+            
+    def check_swing_from_vdd(self, bl_volt, br_volt):
+        """Checks difference on discharging bitline from VDD to see if it is within margin of the RBL height parameter."""
+        if bl_volt < br_volt:
+            discharge_volt = bl_volt
+        else:
+            discharge_volt = br_volt
+        desired_bl_volt = tech.parameter["rbl_height_percentage"]*self.vdd_voltage
+        debug.info(1, "Active bitline={:.3f}v, Desired bitline={:.3f}v".format(discharge_volt,desired_bl_volt))
+        vdd_error_margin = .2 #20% of vdd margin for bitline, a little high for now.
+        if abs(discharge_volt - desired_bl_volt) > vdd_error_margin*self.vdd_voltage:
+            debug.warning("Bitline voltage is not within {}% Vdd margin. Delay chain/RBL could need resizing.".format(vdd_error_margin*100))
+    
+    def check_differential_swing(self, bl_volt, br_volt):
+        """This check looks at the difference between the bitline voltages. This needs to be large enough to prevent
+           sensing errors."""
+        bitline_swing = abs(bl_volt-br_volt)
+        debug.info(1,"Bitline swing={:.3f}v".format(bitline_swing))
+        vdd_error_margin = .2 #20% of vdd margin for bitline, a little high for now.
+        if bitline_swing < vdd_error_margin*self.vdd_voltage:
+            debug.warning("Bitline swing less than {}% Vdd margin. Sensing errors more likely to occur.".format(vdd_error_margin))
+            
     def analyze(self, probe_address, probe_data, slews, loads):
         """Measures the bitline swing of the differential bitlines (bl/br) at 50% s_en """
         self.set_probe(probe_address, probe_data)
@@ -141,10 +232,10 @@ class bitline_delay(delay):
         debug.info(1,"Bitline swing test: corner {}".format(self.corner))
         (success, results)=self.run_delay_simulation()
         debug.check(success, "Bitline Failed: period {}".format(self.period))
-        for mname in self.bitline_meas_names:
-            bitline_swings[mname] = results[read_port][mname]
-        debug.info(1,"Bitline values (bl/br): {}".format(bitline_swings))
-        return bitline_swings
+        debug.info(1,"Bitline values (voltages/delays):\n\t {}".format(results[read_port]))
+        self.check_bitline_all_results(results)
+        
+        return results
 
         
     
diff --git a/compiler/characterizer/charutils.py b/compiler/characterizer/charutils.py
index a2140e51..061972cf 100644
--- a/compiler/characterizer/charutils.py
+++ b/compiler/characterizer/charutils.py
@@ -80,3 +80,10 @@ def convert_to_float(number):
         debug.error("Invalid number: {0}".format(number),1)
 
     return float_value
+
+def check_dict_values_is_float(dict):
+    """Checks if all the values are floats. Useful for checking failed Spice measurements."""
+    for key, value in dict.items():
+            if type(value)!=float:
+                return False
+    return True
\ No newline at end of file
diff --git a/compiler/characterizer/delay.py b/compiler/characterizer/delay.py
index 9e0543d1..7aa9641d 100644
--- a/compiler/characterizer/delay.py
+++ b/compiler/characterizer/delay.py
@@ -8,6 +8,7 @@ from .charutils import *
 import utils
 from globals import OPTS
 from .simulation import simulation
+from .measurements import *
 
 class delay(simulation):
     """Functions to measure the delay and power of an SRAM at a given address and
@@ -35,17 +36,92 @@ class delay(simulation):
         self.period = 0
         self.set_load_slew(0,0)
         self.set_corner(corner)
-        self.create_signal_names()
-        
-        #Create global measure names. Should maybe be an input at some point.
-        self.create_measurement_names()
         
     def create_measurement_names(self):
         """Create measurement names. The names themselves currently define the type of measurement"""
         #Altering the names will crash the characterizer. TODO: object orientated approach to the measurements.
         self.delay_meas_names = ["delay_lh", "delay_hl", "slew_lh", "slew_hl"]
         self.power_meas_names = ["read0_power", "read1_power", "write0_power", "write1_power"]
+        self.voltage_when_names = ["volt_bl", "volt_br"]
+        self.bitline_delay_names = ["delay_bl", "delay_br"]
+       
+    def create_measurement_objects(self):
+        """Create the measurements used for read and write ports"""
+        self.create_read_port_measurement_objects()
+        self.create_write_port_measurement_objects()
+
+    def create_read_port_measurement_objects(self):
+        """Create the measurements used for read ports: delays, slews, powers"""
         
+        self.read_meas_objs = []
+        trig_delay_name = "clk{0}"
+        targ_name = "{0}{1}_{2}".format(self.dout_name,"{}",self.probe_data) #Empty values are the port and probe data bit
+        self.read_meas_objs.append(delay_measure("delay_lh", trig_delay_name, targ_name, "RISE", "RISE", measure_scale=1e9))
+        self.read_meas_objs[-1].meta_str = "read1" #Used to index time delay values when measurements written to spice file.
+        self.read_meas_objs.append(delay_measure("delay_hl", trig_delay_name, targ_name, "FALL", "FALL", measure_scale=1e9))
+        self.read_meas_objs[-1].meta_str = "read0"
+        
+        self.read_meas_objs.append(slew_measure("slew_lh", targ_name, "RISE", measure_scale=1e9))
+        self.read_meas_objs[-1].meta_str = "read1"
+        self.read_meas_objs.append(slew_measure("slew_hl", targ_name, "FALL", measure_scale=1e9))
+        self.read_meas_objs[-1].meta_str = "read0"
+        
+        self.read_meas_objs.append(power_measure("read1_power", "RISE", measure_scale=1e3))
+        self.read_meas_objs[-1].meta_str = "read1"
+        self.read_meas_objs.append(power_measure("read0_power", "FALL", measure_scale=1e3))
+        self.read_meas_objs[-1].meta_str = "read0"
+        
+        #This will later add a half-period to the spice time delay. Only for reading 0.
+        for obj in self.read_meas_objs:
+            if obj.meta_str is "read0":
+                obj.meta_add_delay = True
+
+        trig_name = "Xsram.s_en{}" #Sense amp enable
+        if len(self.all_ports) == 1: #special naming case for single port sram bitlines which does not include the port in name
+            port_format = ""
+        else:
+            port_format = "{}"
+        
+        bl_name = "Xsram.Xbank0.bl{}_{}".format(port_format, self.bitline_column)
+        br_name = "Xsram.Xbank0.br{}_{}".format(port_format, self.bitline_column)
+        self.read_meas_objs.append(voltage_when_measure(self.voltage_when_names[0], trig_name, bl_name, "RISE", .5))
+        self.read_meas_objs.append(voltage_when_measure(self.voltage_when_names[1], trig_name, br_name, "RISE", .5))
+        
+        #These are read values but need to be separated for unique error checking.
+        self.create_bitline_delay_measurement_objects()
+    
+    def create_bitline_delay_measurement_objects(self):
+        """Create the measurements used for bitline delay values. Due to unique error checking, these are separated from other measurements.
+           These measurements are only associated with read values
+        """
+        self.bitline_delay_objs = []
+        trig_name = "clk{0}"
+        if len(self.all_ports) == 1: #special naming case for single port sram bitlines which does not include the port in name
+            port_format = ""
+        else:
+            port_format = "{}"
+        bl_name = "Xsram.Xbank0.bl{}_{}".format(port_format, self.bitline_column)
+        br_name = "Xsram.Xbank0.br{}_{}".format(port_format, self.bitline_column)
+        targ_val = (self.vdd_voltage - tech.spice["v_threshold_typical"])/self.vdd_voltage #Calculate as a percentage of vdd
+        
+        targ_name = "{0}{1}_{2}".format(self.dout_name,"{}",self.probe_data) #Empty values are the port and probe data bit
+        self.bitline_delay_objs.append(delay_measure(self.bitline_delay_names[0], trig_name, bl_name, "FALL", "FALL", targ_vdd=targ_val, measure_scale=1e9))
+        self.bitline_delay_objs[-1].meta_str = "read0"
+        self.bitline_delay_objs.append(delay_measure(self.bitline_delay_names[1], trig_name, br_name, "FALL", "FALL", targ_vdd=targ_val, measure_scale=1e9))
+        self.bitline_delay_objs[-1].meta_str = "read1"
+        #Enforces the time delay on the bitline measurements for read0 or read1
+        for obj in self.bitline_delay_objs:
+            obj.meta_add_delay = True
+        
+    def create_write_port_measurement_objects(self):
+        """Create the measurements used for read ports: delays, slews, powers"""
+        self.write_meas_objs = []
+
+        self.write_meas_objs.append(power_measure("write1_power", "RISE", measure_scale=1e3))
+        self.write_meas_objs[-1].meta_str = "write1"
+        self.write_meas_objs.append(power_measure("write0_power", "FALL", measure_scale=1e3))
+        self.write_meas_objs[-1].meta_str = "write0"
+     
     def create_signal_names(self):
         self.addr_name = "A"
         self.din_name = "DIN"
@@ -198,86 +274,75 @@ class delay(simulation):
 
         self.sf.close()
         
-    def get_delay_meas_values(self, delay_name, port):
-        """Get the values needed to generate a Spice measurement statement based on the name of the measurement."""
-        debug.check('lh' in delay_name or 'hl' in delay_name, "Measure command {0} does not contain direction (lh/hl)")
-        trig_clk_name = "clk{0}".format(port)
-        meas_name="{0}{1}".format(delay_name, port)
-        targ_name = "{0}".format("{0}{1}_{2}".format(self.dout_name,port,self.probe_data))
-        half_vdd = 0.5 * self.vdd_voltage
-        trig_slew_low = 0.1 * self.vdd_voltage
-        targ_slew_high = 0.9 * self.vdd_voltage
-        if 'delay' in delay_name:
-            trig_val = half_vdd
-            targ_val = half_vdd
-            trig_name = trig_clk_name
-            if 'lh' in delay_name:
-                trig_dir="RISE" 
-                targ_dir="RISE"
-                trig_td = targ_td = self.cycle_times[self.measure_cycles[port]["read1"]]
-            else:
-                trig_dir="FALL" 
-                targ_dir="FALL"
-                trig_td = targ_td = self.cycle_times[self.measure_cycles[port]["read0"]] 
-                    
-        elif 'slew' in delay_name:
-            trig_name = targ_name
-            if 'lh' in delay_name:
-                trig_val = trig_slew_low
-                targ_val = targ_slew_high
-                targ_dir = trig_dir = "RISE"
-                trig_td = targ_td = self.cycle_times[self.measure_cycles[port]["read1"]]
-            else:
-                trig_val = targ_slew_high 
-                targ_val = trig_slew_low
-                targ_dir = trig_dir = "FALL"
-                trig_td = targ_td = self.cycle_times[self.measure_cycles[port]["read0"]] 
+    def get_read_measure_variants(self, port, measure_obj):
+        """Checks the measurement object and calls respective function for related measurement inputs."""
+        meas_type = type(measure_obj)
+        if meas_type is delay_measure or meas_type is slew_measure:
+            return self.get_delay_measure_variants(port, measure_obj)
+        elif meas_type is power_measure:
+            return self.get_power_measure_variants(port, measure_obj, "read")
+        elif meas_type is voltage_when_measure:
+            return self.get_volt_when_measure_variants(port, measure_obj)
         else:
-            debug.error(1, "Measure command {0} not recognized".format(delay_name))
-        return (meas_name,trig_name,targ_name,trig_val,targ_val,trig_dir,targ_dir,trig_td,targ_td)
-        
+            debug.error("Input function not defined for measurement type={}".format(meas_type))
+            
+    def get_delay_measure_variants(self, port, delay_obj):
+        """Get the measurement values that can either vary from simulation to simulation (vdd, address) or port to port (time delays)"""
+        #Return value is intended to match the delay measure format:  trig_td, targ_td, vdd, port
+        #vdd is arguably constant as that is true for a single lib file.
+        if delay_obj.meta_str == "read0":
+            #Falling delay are measured starting from neg. clk edge. Delay adjusted to that.
+            meas_cycle_delay = self.cycle_times[self.measure_cycles[port][delay_obj.meta_str]]
+        elif delay_obj.meta_str == "read1":
+            meas_cycle_delay = self.cycle_times[self.measure_cycles[port][delay_obj.meta_str]]
+        else:
+            debug.error("Unrecognised delay Index={}".format(delay_obj.meta_str),1)
+            
+        if delay_obj.meta_add_delay:    
+            meas_cycle_delay += self.period/2
+            
+        return (meas_cycle_delay, meas_cycle_delay, self.vdd_voltage, port)
+    
+    def get_power_measure_variants(self, port, power_obj, operation):
+        """Get the measurement values that can either vary port to port (time delays)"""
+        #Return value is intended to match the power measure format:  t_initial, t_final, port
+        t_initial = self.cycle_times[self.measure_cycles[port][power_obj.meta_str]]
+        t_final = self.cycle_times[self.measure_cycles[port][power_obj.meta_str]+1]
+    
+        return (t_initial, t_final, port)
+    
+    def get_volt_when_measure_variants(self, port, power_obj):
+        """Get the measurement values that can either vary port to port (time delays)"""
+        #Only checking 0 value reads for now.
+        t_trig = meas_cycle_delay = self.cycle_times[self.measure_cycles[port]["read0"]]
+
+        return (t_trig, self.vdd_voltage, port)
+    
     def write_delay_measures_read_port(self, port):
         """
         Write the measure statements to quantify the delay and power results for a read port.
         """
         # add measure statements for delays/slews
-        for dname in self.delay_meas_names:
-            meas_values = self.get_delay_meas_values(dname, port)
-            self.stim.gen_meas_delay(*meas_values)
+        for measure in self.read_meas_objs+self.bitline_delay_objs:
+            measure_variant_inp_tuple = self.get_read_measure_variants(port, measure)
+            measure.write_measure(self.stim, measure_variant_inp_tuple)
+
+    def get_write_measure_variants(self, port, measure_obj):
+        """Checks the measurement object and calls respective function for related measurement inputs."""
+        meas_type = type(measure_obj)
+        if meas_type is power_measure:
+            return self.get_power_measure_variants(port, measure_obj, "write")
+        else:
+            debug.error("Input function not defined for measurement type={}".format(meas_type))        
             
-        # add measure statements for power
-        for pname in self.power_meas_names:
-            if "read" not in pname:
-                continue
-            #Different naming schemes are used for the measure cycle dict and measurement names. 
-            #TODO: make them the same so they can be indexed the same.
-            if '1' in pname:
-                t_initial = self.cycle_times[self.measure_cycles[port]["read1"]]
-                t_final = self.cycle_times[self.measure_cycles[port]["read1"]+1]
-            elif '0' in pname:
-                t_initial = self.cycle_times[self.measure_cycles[port]["read0"]]
-                t_final = self.cycle_times[self.measure_cycles[port]["read0"]+1]
-            self.stim.gen_meas_power(meas_name="{0}{1}".format(pname, port),
-                                     t_initial=t_initial,
-                                     t_final=t_final)
-       
     def write_delay_measures_write_port(self, port):
         """
         Write the measure statements to quantify the power results for a write port.
         """
         # add measure statements for power
-        for pname in self.power_meas_names:
-            if "write" not in pname:
-                continue
-            t_initial = self.cycle_times[self.measure_cycles[port]["write0"]]
-            t_final = self.cycle_times[self.measure_cycles[port]["write0"]+1]
-            if '1' in pname:
-                t_initial = self.cycle_times[self.measure_cycles[port]["write1"]]
-                t_final = self.cycle_times[self.measure_cycles[port]["write1"]+1]
-        
-            self.stim.gen_meas_power(meas_name="{0}{1}".format(pname, port),
-                                     t_initial=t_initial,
-                                     t_final=t_final)
+        for measure in self.write_meas_objs:
+            measure_variant_inp_tuple = self.get_write_measure_variants(port, measure)
+            measure.write_measure(self.stim, measure_variant_inp_tuple)
 
     def write_delay_measures(self):
         """
@@ -385,28 +450,7 @@ class delay(simulation):
             previous_period = self.period
         debug.info(1, "Found feasible_period: {0}ns".format(self.period))
         return feasible_delays
-           
-                
-    def parse_values(self, values_names, port, mult = 1.0):
-        """Parse multiple values in the timing output file. Optional multiplier.
-           Return a dict of the input names and values. Port used for parsing file.
-        """
-        values = []
-        all_values_floats = True
-        for vname in values_names:
-            #ngspice converts all measure characters to lowercase, not tested on other sims
-            value = parse_spice_list("timing", "{0}{1}".format(vname.lower(), port)) 
-            #Check if any of the values fail to parse
-            if type(value)!=float: 
-                all_values_floats = False
-            values.append(value)
-            
-        #Apply Multiplier only if all values are floats. Let other check functions handle this error.
-        if all_values_floats:
-            return {values_names[i]:values[i]*mult for i in range(len(values))}
-        else:
-            return {values_names[i]:values[i] for i in range(len(values))}
-            
+    
     def run_delay_simulation(self):
         """
         This tries to simulate a period and checks if the result works. If
@@ -427,33 +471,45 @@ class delay(simulation):
         #Too much duplicate code here. Try reducing
         for port in self.targ_read_ports:
             debug.info(2, "Check delay values for port {}".format(port))
-            delay_names = [mname for mname in self.delay_meas_names]
-            delays = self.parse_values(delay_names, port, 1e9) # scale delays to ns
-            if not self.check_valid_delays(delays):
-                return (False,{})
-            result[port].update(delays)
+            read_port_dict = {}
+            #Get measurements from output file
+            for measure in self.read_meas_objs:
+                read_port_dict[measure.name] = measure.retrieve_measure(port=port)
+            
+            #Check timing for read ports. Power is only checked if it was read correctly
+            if not self.check_valid_delays(read_port_dict):
+                return (False,{})
+            if not check_dict_values_is_float(read_port_dict):
+                debug.error("Failed to Measure Read Port Values:\n\t\t{0}".format(read_port_dict),1) #Printing the entire dict looks bad.    
+                
+            result[port].update(read_port_dict)
+            
+            bitline_delay_dict = self.evaluate_bitline_delay(port)
+            result[port].update(bitline_delay_dict)
             
-            power_names = [mname for mname in self.power_meas_names if 'read' in mname]
-            powers = self.parse_values(power_names, port, 1e3) # scale power to mw
-            #Check that power parsing worked.
-            for name, power in powers.items():
-                if type(power)!=float:
-                    debug.error("Failed to Parse Power Values:\n\t\t{0}".format(powers),1) #Printing the entire dict looks bad.
-            result[port].update(powers)
-        
         for port in self.targ_write_ports:
-            power_names = [mname for mname in self.power_meas_names if 'write' in mname]
-            powers = self.parse_values(power_names, port, 1e3) # scale power to mw
-            #Check that power parsing worked.
-            for name, power in powers.items():
-                if type(power)!=float:
-                    debug.error("Failed to Parse Power Values:\n\t\t{0}".format(powers),1) #Printing the entire dict looks bad.
-            result[port].update(powers)
+            write_port_dict = {}
+            for measure in self.write_meas_objs:
+                write_port_dict[measure.name] = measure.retrieve_measure(port=port)
+
+            if not check_dict_values_is_float(write_port_dict):
+                debug.error("Failed to Measure Write Port Values:\n\t\t{0}".format(write_port_dict),1) #Printing the entire dict looks bad. 
+            result[port].update(write_port_dict)
             
         # The delay is from the negative edge for our SRAM
         return (True,result)
 
-
+    def evaluate_bitline_delay(self, port):
+        """Parse and check the bitline delay. One of the measurements is expected to fail which warrants its own function."""
+        bl_delay_meas_dict = {}
+        values_added = 0 #For error checking
+        for measure in self.bitline_delay_objs:
+            bl_delay_val = measure.retrieve_measure(port=port)
+            if type(bl_delay_val) != float or 0 > bl_delay_val or bl_delay_val > self.period/2: #Only add if value is valid, do not error.
+                debug.error("Bitline delay measurement failed: half-period={}, {}={}".format(self.period/2, measure.name, bl_delay_val),1)
+            bl_delay_meas_dict[measure.name] = bl_delay_val
+        return bl_delay_meas_dict
+        
     def run_power_simulation(self):
         """ 
         This simulates a disabled SRAM to get the leakage power when it is off.
@@ -478,13 +534,13 @@ class delay(simulation):
         #key=raw_input("press return to continue")
         return (leakage_power*1e3, trim_leakage_power*1e3)
     
-    def check_valid_delays(self, delay_dict):
+    def check_valid_delays(self, result_dict):
         """ Check if the measurements are defined and if they are valid. """
         #Hard coded names currently
-        delay_hl = delay_dict["delay_hl"]
-        delay_lh = delay_dict["delay_lh"]
-        slew_hl = delay_dict["slew_hl"]
-        slew_lh = delay_dict["slew_lh"]
+        delay_hl = result_dict["delay_hl"]
+        delay_lh = result_dict["delay_lh"]
+        slew_hl = result_dict["slew_hl"]
+        slew_lh = result_dict["slew_lh"]
         period_load_slew_str = "period {0} load {1} slew {2}".format(self.period,self.load, self.slew)
         
         # if it failed or the read was longer than a period
@@ -610,9 +666,22 @@ class delay(simulation):
         functions in this characterizer besides analyze."""
         self.probe_address = probe_address
         self.probe_data = probe_data
-
+        self.bitline_column = self.get_data_bit_column_number(probe_address, probe_data)
+        self.wordline_row = self.get_address_row_number(probe_address)
         self.prepare_netlist()
         
+    def get_data_bit_column_number(self, probe_address, probe_data):
+        """Calculates bitline column number of data bit under test using bit position and mux size"""
+        if self.sram.col_addr_size>0:
+            col_address = int(probe_address[0:self.sram.col_addr_size],2)
+        else:
+            col_address = 0
+        bl_column = int(self.sram.words_per_row*probe_data + col_address)
+        return bl_column 
+
+    def get_address_row_number(self, probe_address):
+        """Calculates wordline row number of data bit under test using address and column mux size"""
+        return int(probe_address[self.sram.col_addr_size:],2)
 
     def prepare_netlist(self):
         """ Prepare a trimmed netlist and regular netlist. """
@@ -645,6 +714,9 @@ class delay(simulation):
         char_sram_data = {}
         
         self.set_probe(probe_address, probe_data)
+        self.create_signal_names()
+        self.create_measurement_names()
+        self.create_measurement_objects()
         
         self.load=max(loads)
         self.slew=max(slews)
@@ -828,7 +900,8 @@ class delay(simulation):
         """
         if OPTS.num_rw_ports > 1 or OPTS.num_w_ports > 0 and OPTS.num_r_ports > 0:
             debug.warning("Analytical characterization results are not supported for multiport.")
-        
+        self.create_signal_names()
+        self.create_measurement_names()
         power = self.analytical_power(slews, loads)
         port_data = self.get_empty_measure_data_dict()
         for slew in slews:
@@ -845,7 +918,9 @@ class delay(simulation):
                             port_data[port][mname].append(bank_delay[port].slew/1e3)
                         else:
                             debug.error("Measurement name not recognized: {}".format(mname),1)
-        sram_data = { "min_period": 0, 
+        period_margin = 0.1
+        risefall_delay = bank_delay[self.read_ports[0]].delay/1e3
+        sram_data = { "min_period":risefall_delay*2*period_margin, 
                       "leakage_power": power.leakage}                    
          
         return (sram_data,port_data)
@@ -890,7 +965,7 @@ class delay(simulation):
             
     def get_empty_measure_data_dict(self):
         """Make a dict of lists for each type of delay and power measurement to append results to"""
-        measure_names = self.delay_meas_names + self.power_meas_names
+        measure_names = self.delay_meas_names + self.power_meas_names + self.voltage_when_names + self.bitline_delay_names
         #Create list of dicts. List lengths is # of ports. Each dict maps the measurement names to lists.
         measure_data = [{mname:[] for mname in measure_names} for i in self.all_ports]
         return measure_data
diff --git a/compiler/characterizer/logical_effort.py b/compiler/characterizer/logical_effort.py
index bf8c1585..c80e69a2 100644
--- a/compiler/characterizer/logical_effort.py
+++ b/compiler/characterizer/logical_effort.py
@@ -10,7 +10,8 @@ class logical_effort():
     min_inv_cin = 1+beta
     pinv=parameter["min_inv_para_delay"]
     
-    def __init__(self, size, cin, cout, parasitic, out_is_rise=True):
+    def __init__(self, name, size, cin, cout, parasitic, out_is_rise=True):
+        self.name = name
         self.cin = cin
         self.cout = cout
         self.logical_effort = (self.cin/size)/logical_effort.min_inv_cin
@@ -19,8 +20,13 @@ class logical_effort():
         self.is_rise = out_is_rise
      
     def __str__(self):
-        return "g=" + str(self.logical_effort) + ", h=" + str(self.eletrical_effort) + ", p=" + str(self.parasitic_scale)+"*pinv, rise_delay="+str(self.is_rise)
-    
+        return  "Name={}, g={}, h={}, p={}*pinv, rise_delay={}".format(self.name,
+                                                                       self.logical_effort,
+                                                                       self.eletrical_effort,
+                                                                       self.parasitic_scale,
+                                                                       self.is_rise
+                                                                       ) 
+
     def get_stage_effort(self):
         return  self.logical_effort*self.eletrical_effort
         
@@ -29,6 +35,10 @@ class logical_effort():
     
     def get_stage_delay(self, pinv):
         return self.get_stage_effort()+self.get_parasitic_delay(pinv)
+
+def calculate_delays(stage_effort_list, pinv):
+    """Convert stage effort objects to list of delay values"""
+    return [stage.get_stage_delay(pinv) for stage in stage_effort_list]
     
 def calculate_relative_delay(stage_effort_list, pinv=parameter["min_inv_para_delay"]):
     """Calculates the total delay of a given delay path made of a list of logical effort objects."""
@@ -40,7 +50,7 @@ def calculate_relative_rise_fall_delays(stage_effort_list, pinv=parameter["min_i
     debug.info(2, "Calculating rise/fall relative delays")
     total_rise_delay, total_fall_delay = 0,0
     for stage in stage_effort_list:
-        debug.info(3, stage)
+        debug.info(2, stage)
         if stage.is_rise:
             total_rise_delay += stage.get_stage_delay(pinv)
         else:
diff --git a/compiler/characterizer/measurements.py b/compiler/characterizer/measurements.py
new file mode 100644
index 00000000..e3d16584
--- /dev/null
+++ b/compiler/characterizer/measurements.py
@@ -0,0 +1,159 @@
+import debug
+from tech import drc, parameter, spice
+from abc import ABC, abstractmethod
+from .stimuli import *
+from .charutils import *
+
+class spice_measurement(ABC):
+    """Base class for spice stimulus measurements."""
+    def __init__(self, measure_name, measure_scale=None):
+        #Names must be unique for correct spice simulation, but not enforced here.
+        self.name = measure_name
+        self.measure_scale = measure_scale
+        #Some meta values used externally. variables are added here for consistency accross the objects
+        self.meta_str = None 
+        self.meta_add_delay = False
+    @abstractmethod
+    def get_measure_function(self):
+        return None    
+        
+    @abstractmethod
+    def get_measure_values(self):
+        return None
+        
+    def write_measure(self, stim_obj, input_tuple):
+        measure_func = self.get_measure_function()
+        if measure_func == None:
+            debug.error("Did not set measure function",1)
+        measure_vals = self.get_measure_values(*input_tuple)
+        measure_func(stim_obj, *measure_vals)
+    
+    def retrieve_measure(self, port=""):
+        value = parse_spice_list("timing", "{0}{1}".format(self.name.lower(), port)) 
+        if type(value)!=float or self.measure_scale == None: 
+            return value
+        else:
+            return value*self.measure_scale
+           
+class delay_measure(spice_measurement):
+    """Generates a spice measurement for the delay of 50%-to-50% points of two signals."""
+    
+    def __init__(self, measure_name, trig_name, targ_name,  trig_dir_str, targ_dir_str, trig_vdd=0.5, targ_vdd=0.5, measure_scale=None):
+        spice_measurement.__init__(self, measure_name, measure_scale)
+        self.set_meas_constants(trig_name, targ_name, trig_dir_str, targ_dir_str, trig_vdd, targ_vdd)
+    
+    def get_measure_function(self):
+        return stimuli.gen_meas_delay
+    
+    def set_meas_constants(self, trig_name, targ_name, trig_dir_str, targ_dir_str, trig_vdd, targ_vdd):
+        """Set the constants for this measurement: signal names, directions, and trigger scales"""
+        self.trig_dir_str = trig_dir_str
+        self.targ_dir_str = targ_dir_str
+        
+        self.trig_val_of_vdd = trig_vdd 
+        self.targ_val_of_vdd = targ_vdd
+        
+        self.trig_name_no_port = trig_name
+        self.targ_name_no_port = targ_name
+        
+        #Time delays and ports are variant and needed as inputs when writing the measurement
+        
+    def get_measure_values(self, trig_td, targ_td, vdd_voltage, port=None):    
+        """Constructs inputs to stimulus measurement function. Variant values are inputs here."""
+        trig_val = self.trig_val_of_vdd * vdd_voltage
+        targ_val = self.targ_val_of_vdd * vdd_voltage
+        
+        if port != None:
+            #For dictionary indexing reasons, the name is formatted differently than the signals
+            meas_name = "{}{}".format(self.name, port)
+            trig_name = self.trig_name_no_port.format(port)
+            targ_name = self.targ_name_no_port.format(port)
+        else:
+            meas_name = self.name
+            trig_name = self.trig_name_no_port
+            targ_name = self.targ_name_no_port
+
+        return (meas_name,trig_name,targ_name,trig_val,targ_val,self.trig_dir_str,self.targ_dir_str,trig_td,targ_td)            
+
+class slew_measure(delay_measure):        
+    
+    def __init__(self, measure_name, signal_name, slew_dir_str, measure_scale=None):
+        spice_measurement.__init__(self, measure_name, measure_scale)
+        self.set_meas_constants(signal_name, slew_dir_str)
+    
+    def set_meas_constants(self, signal_name, slew_dir_str):
+        """Set the values needed to generate a Spice measurement statement based on the name of the measurement."""
+        self.trig_dir_str = slew_dir_str
+        self.targ_dir_str = slew_dir_str
+        
+        if slew_dir_str == "RISE":
+            self.trig_val_of_vdd = 0.1 
+            self.targ_val_of_vdd = 0.9
+        elif slew_dir_str == "FALL":
+            self.trig_val_of_vdd = 0.9 
+            self.targ_val_of_vdd = 0.1
+        else:
+            debug.error("Unrecognised slew measurement direction={}".format(slew_dir_str),1)
+        
+        self.trig_name_no_port = signal_name
+        self.targ_name_no_port = signal_name
+        
+        #Time delays and ports are variant and needed as inputs when writing the measurement 
+ 
+class power_measure(spice_measurement):
+    """Generates a spice measurement for the average power between two time points."""
+    
+    def __init__(self, measure_name, power_type="", measure_scale=None):
+        spice_measurement.__init__(self, measure_name, measure_scale)
+        self.set_meas_constants(power_type)
+    
+    def get_measure_function(self):
+        return stimuli.gen_meas_power
+    
+    def set_meas_constants(self, power_type):
+        """Sets values useful for power simulations. This value is only meta related to the lib file (rise/fall)"""
+        #Not needed for power simulation
+        self.power_type = power_type #Expected to be  "RISE"/"FALL"
+        
+    def get_measure_values(self, t_initial, t_final, port=None):    
+        """Constructs inputs to stimulus measurement function. Variant values are inputs here."""
+        if port != None:
+            meas_name = "{}{}".format(self.name, port)
+        else:
+            meas_name = self.name
+        return (meas_name,t_initial,t_final)  
+        
+class voltage_when_measure(spice_measurement):        
+    """Generates a spice measurement to measure the voltage of a signal based on the voltage of another."""
+    
+    def __init__(self, measure_name, trig_name, targ_name, trig_dir_str, trig_vdd, measure_scale=None):
+        spice_measurement.__init__(self, measure_name, measure_scale)
+        self.set_meas_constants(trig_name, targ_name, trig_dir_str, trig_vdd)
+    
+    def get_measure_function(self):
+        return stimuli.gen_meas_find_voltage
+    
+    def set_meas_constants(self, trig_name, targ_name, trig_dir_str, trig_vdd):
+        """Sets values useful for power simulations. This value is only meta related to the lib file (rise/fall)"""
+        self.trig_dir_str = trig_dir_str
+        self.trig_val_of_vdd = trig_vdd 
+  
+        self.trig_name_no_port = trig_name
+        self.targ_name_no_port = targ_name
+        
+    def get_measure_values(self, trig_td, vdd_voltage, port=None):    
+        """Constructs inputs to stimulus measurement function. Variant values are inputs here."""
+        
+        if port != None:
+            #For dictionary indexing reasons, the name is formatted differently than the signals
+            meas_name = "{}{}".format(self.name, port)
+            trig_name = self.trig_name_no_port.format(port)
+            targ_name = self.targ_name_no_port.format(port)
+        else:
+            meas_name = self.name
+            trig_name = self.trig_name_no_port
+            targ_name = self.targ_name_no_port
+
+        trig_voltage = self.trig_val_of_vdd*vdd_voltage
+            
+        return (meas_name,trig_name,targ_name,trig_voltage,self.trig_dir_str,trig_td)
\ No newline at end of file
diff --git a/compiler/characterizer/model_check.py b/compiler/characterizer/model_check.py
new file mode 100644
index 00000000..88e0b96a
--- /dev/null
+++ b/compiler/characterizer/model_check.py
@@ -0,0 +1,336 @@
+import sys,re,shutil
+import debug
+import tech
+import math
+from .stimuli import *
+from .trim_spice import *
+from .charutils import *
+import utils
+from globals import OPTS
+from .delay import delay
+from .measurements import *
+
+class model_check(delay):
+    """Functions to test for the worst case delay in a target SRAM
+
+    The current worst case determines a feasible period for the SRAM then tests
+    several bits and record the delay and differences between the bits.
+
+    """
+
+    def __init__(self, sram, spfile, corner):
+        delay.__init__(self,sram,spfile,corner)
+        self.period = tech.spice["feasible_period"]
+        self.create_data_names()
+        
+    def create_data_names(self):
+        self.wl_meas_name, self.wl_model_name = "wl_measures", "wl_model"
+        self.sae_meas_name, self.sae_model_name = "sae_measures", "sae_model"
+        
+    def create_measurement_names(self):
+        """Create measurement names. The names themselves currently define the type of measurement"""
+        #Create delay measurement names
+        wl_en_driver_delay_names = ["delay_wl_en_dvr{}_".format(stage) for stage in range(1,self.get_num_wl_en_driver_stages())]
+        wl_driver_delay_names = ["delay_wl_dvr{}_".format(stage) for stage in range(1,self.get_num_wl_driver_stages())]
+        sen_driver_delay_names = ["delay_sen_dvr{}_".format(stage) for stage in range(1,self.get_num_sen_driver_stages())]
+        dc_delay_names = ["delay_delay_chain_stage{}_".format(stage) for stage in range(1,self.get_num_delay_stages()+1)]
+        self.wl_delay_meas_names = wl_en_driver_delay_names+["delay_wl_en", "delay_wl_bar"]+wl_driver_delay_names+["delay_wl"]
+        self.rbl_delay_meas_names = ["delay_gated_clk_nand", "delay_delay_chain_in"]+dc_delay_names
+        self.sae_delay_meas_names = ["delay_pre_sen"]+sen_driver_delay_names+["delay_sen"]
+
+        self.delay_chain_indices = (len(self.rbl_delay_meas_names)-len(dc_delay_names), len(self.rbl_delay_meas_names))
+        #Create slew measurement names
+        wl_en_driver_slew_names = ["slew_wl_en_dvr{}_".format(stage) for stage in range(1,self.get_num_wl_en_driver_stages())]
+        wl_driver_slew_names = ["slew_wl_dvr{}_".format(stage) for stage in range(1,self.get_num_wl_driver_stages())]
+        sen_driver_slew_names = ["slew_sen_dvr{}_".format(stage) for stage in range(1,self.get_num_sen_driver_stages())]
+        dc_slew_names = ["slew_delay_chain_stage{}_".format(stage) for stage in range(1,self.get_num_delay_stages()+1)]
+        self.wl_slew_meas_names = ["slew_wl_gated_clk_bar"]+wl_en_driver_slew_names+["slew_wl_en", "slew_wl_bar"]+wl_driver_slew_names+["slew_wl"]
+        self.rbl_slew_meas_names = ["slew_rbl_gated_clk_bar","slew_gated_clk_nand", "slew_delay_chain_in"]+dc_slew_names
+        self.sae_slew_meas_names = ["slew_replica_bl0", "slew_pre_sen"]+sen_driver_slew_names+["slew_sen"]
+       
+    def create_signal_names(self):
+        """Creates list of the signal names used in the spice file along the wl and sen paths."""
+        delay.create_signal_names(self)
+        #Signal names are all hardcoded, need to update to make it work for probe address and different configurations.
+        wl_en_driver_signals = ["Xsram.Xcontrol0.Xbuf_wl_en.Zb{}_int".format(stage) for stage in range(1,self.get_num_wl_en_driver_stages())]
+        wl_driver_signals = ["Xsram.Xbank0.Xwordline_driver0.Xwl_driver_inv{}.Zb{}_int".format(self.wordline_row, stage) for stage in range(1,self.get_num_wl_driver_stages())]
+        sen_driver_signals = ["Xsram.Xcontrol0.Xbuf_s_en.Zb{}_int".format(stage) for stage in range(1,self.get_num_sen_driver_stages())]
+        delay_chain_signal_names = ["Xsram.Xcontrol0.Xreplica_bitline.Xdelay_chain.dout_{}".format(stage) for stage in range(1,self.get_num_delay_stages())] 
+        
+        self.wl_signal_names = ["Xsram.Xcontrol0.gated_clk_bar"]+\
+                               wl_en_driver_signals+\
+                               ["Xsram.wl_en0", "Xsram.Xbank0.Xwordline_driver0.wl_bar_{}".format(self.wordline_row)]+\
+                               wl_driver_signals+\
+                               ["Xsram.Xbank0.wl_{}".format(self.wordline_row)]
+        pre_delay_chain_names = ["Xsram.Xcontrol0.gated_clk_bar", "Xsram.Xcontrol0.Xand2_rbl_in.zb_int", "Xsram.Xcontrol0.rbl_in"]
+        self.rbl_en_signal_names = pre_delay_chain_names+\
+                                   delay_chain_signal_names+\
+                                   ["Xsram.Xcontrol0.Xreplica_bitline.delayed_en"]
+        self.sae_signal_names = ["Xsram.Xcontrol0.Xreplica_bitline.bl0_0", "Xsram.Xcontrol0.pre_s_en"]+\
+                                sen_driver_signals+\
+                                ["Xsram.s_en0"]
+    
+    def create_measurement_objects(self):
+        """Create the measurements used for read and write ports"""
+        self.create_wordline_measurement_objects()
+        self.create_sae_measurement_objects()
+        self.all_measures = self.wl_meas_objs+self.sae_meas_objs
+    
+    def create_wordline_measurement_objects(self):
+        """Create the measurements to measure the wordline path from the gated_clk_bar signal"""
+        self.wl_meas_objs = []
+        trig_dir = "RISE"
+        targ_dir = "FALL"
+        
+        for i in range(1, len(self.wl_signal_names)):
+            self.wl_meas_objs.append(delay_measure(self.wl_delay_meas_names[i-1], 
+                                                   self.wl_signal_names[i-1], 
+                                                   self.wl_signal_names[i], 
+                                                   trig_dir, 
+                                                   targ_dir, 
+                                                   measure_scale=1e9))
+            self.wl_meas_objs.append(slew_measure(self.wl_slew_meas_names[i-1], 
+                                                  self.wl_signal_names[i-1], 
+                                                  trig_dir, 
+                                                  measure_scale=1e9))
+            temp_dir = trig_dir
+            trig_dir = targ_dir
+            targ_dir = temp_dir
+        self.wl_meas_objs.append(slew_measure(self.wl_slew_meas_names[-1], self.wl_signal_names[-1], trig_dir, measure_scale=1e9))
+        
+    def create_sae_measurement_objects(self):
+        """Create the measurements to measure the sense amp enable path from the gated_clk_bar signal. The RBL splits this path into two."""
+        
+        self.sae_meas_objs = []
+        trig_dir = "RISE"
+        targ_dir = "FALL"
+        #Add measurements from gated_clk_bar to RBL
+        for i in range(1, len(self.rbl_en_signal_names)):
+            self.sae_meas_objs.append(delay_measure(self.rbl_delay_meas_names[i-1], 
+                                                    self.rbl_en_signal_names[i-1], 
+                                                    self.rbl_en_signal_names[i], 
+                                                    trig_dir, 
+                                                    targ_dir, 
+                                                    measure_scale=1e9))
+            self.sae_meas_objs.append(slew_measure(self.rbl_slew_meas_names[i-1], 
+                                                   self.rbl_en_signal_names[i-1], 
+                                                   trig_dir, 
+                                                   measure_scale=1e9))
+            temp_dir = trig_dir
+            trig_dir = targ_dir
+            targ_dir = temp_dir
+        self.sae_meas_objs.append(slew_measure(self.rbl_slew_meas_names[-1], 
+                                               self.rbl_en_signal_names[-1], 
+                                               trig_dir, 
+                                               measure_scale=1e9))
+        
+        #Add measurements from rbl_out to sae. Trigger directions do not invert from previous stage due to RBL.
+        trig_dir = "FALL"
+        targ_dir = "RISE"
+        #Add measurements from gated_clk_bar to RBL
+        for i in range(1, len(self.sae_signal_names)):
+            self.sae_meas_objs.append(delay_measure(self.sae_delay_meas_names[i-1], 
+                                                    self.sae_signal_names[i-1], 
+                                                    self.sae_signal_names[i], 
+                                                    trig_dir, 
+                                                    targ_dir, 
+                                                    measure_scale=1e9))
+            self.sae_meas_objs.append(slew_measure(self.sae_slew_meas_names[i-1], 
+                                                   self.sae_signal_names[i-1], 
+                                                   trig_dir, 
+                                                   measure_scale=1e9))
+            temp_dir = trig_dir
+            trig_dir = targ_dir
+            targ_dir = temp_dir
+        self.sae_meas_objs.append(slew_measure(self.sae_slew_meas_names[-1], 
+                                               self.sae_signal_names[-1], 
+                                               trig_dir, 
+                                               measure_scale=1e9))
+        
+    def write_delay_measures(self):
+        """
+        Write the measure statements to quantify the delay and power results for all targeted ports.
+        """
+        self.sf.write("\n* Measure statements for delay and power\n")
+
+        # Output some comments to aid where cycles start and what is happening
+        for comment in self.cycle_comments:
+            self.sf.write("* {}\n".format(comment))
+        
+        for read_port in self.targ_read_ports:
+           self.write_measures_read_port(read_port)
+
+    def get_delay_measure_variants(self, port, measure_obj):
+        """Get the measurement values that can either vary from simulation to simulation (vdd, address) 
+           or port to port (time delays)"""
+        #Return value is intended to match the delay measure format:  trig_td, targ_td, vdd, port
+        #Assuming only read 0 for now
+        if not (type(measure_obj) is delay_measure or type(measure_obj) is slew_measure):
+            debug.error("Measurement not recognized by the model checker.",1)
+        meas_cycle_delay = self.cycle_times[self.measure_cycles[port]["read0"]] + self.period/2
+        return (meas_cycle_delay, meas_cycle_delay, self.vdd_voltage, port)
+    
+    def write_measures_read_port(self, port):
+        """
+        Write the measure statements for all nodes along the wordline path.
+        """
+        # add measure statements for delays/slews
+        for measure in self.all_measures:
+            measure_variant_inp_tuple = self.get_delay_measure_variants(port, measure)
+            measure.write_measure(self.stim, measure_variant_inp_tuple)
+    
+    def get_measurement_values(self, meas_objs, port):
+        """Gets the delays and slews from a specified port from the spice output file and returns them as lists."""
+        delay_meas_list = []  
+        slew_meas_list = [] 
+        for measure in meas_objs:
+            measure_value = measure.retrieve_measure(port=port)
+            if type(measure_value) != float:
+                debug.error("Failed to Measure Value:\n\t\t{}={}".format(measure.name, measure_value),1) 
+            if type(measure) is delay_measure:
+                delay_meas_list.append(measure_value)
+            elif type(measure)is slew_measure:
+                slew_meas_list.append(measure_value)
+            else:
+                debug.error("Measurement object not recognized.",1)
+        return delay_meas_list, slew_meas_list
+        
+    def run_delay_simulation(self):
+        """
+        This tries to simulate a period and checks if the result works. If
+        so, it returns True and the delays, slews, and powers.  It
+        works on the trimmed netlist by default, so powers do not
+        include leakage of all cells.
+        """
+        #Sanity Check
+        debug.check(self.period > 0, "Target simulation period non-positive") 
+        
+        wl_delay_result = [[] for i in self.all_ports]
+        wl_slew_result = [[] for i in self.all_ports]
+        sae_delay_result = [[] for i in self.all_ports]
+        sae_slew_result = [[] for i in self.all_ports]
+        # Checking from not data_value to data_value
+        self.write_delay_stimulus()
+
+        self.stim.run_sim() #running sim prodoces spice output file.
+        
+        #Retrieve the results from the output file
+        for port in self.targ_read_ports:  
+            #Parse and check the voltage measurements
+            wl_delay_result[port], wl_slew_result[port] = self.get_measurement_values(self.wl_meas_objs, port)
+            sae_delay_result[port], sae_slew_result[port] = self.get_measurement_values(self.sae_meas_objs, port)
+        return (True,wl_delay_result, sae_delay_result, wl_slew_result, sae_slew_result)
+  
+    def get_model_delays(self, port):
+        """Get model delays based on port. Currently assumes single RW port."""
+        return self.sram.control_logic_rw.get_wl_sen_delays()
+     
+    def get_num_delay_stages(self):
+        """Gets the number of stages in the delay chain from the control logic"""
+        return len(self.sram.control_logic_rw.replica_bitline.delay_fanout_list)
+    
+    def get_num_delay_stage_fanout(self):
+        """Gets fanout in each stage in the delay chain. Assumes each stage is the same"""
+        return self.sram.control_logic_rw.replica_bitline.delay_fanout_list[0]
+    
+    def get_num_wl_en_driver_stages(self):
+        """Gets the number of stages in the wl_en driver from the control logic"""
+        return self.sram.control_logic_rw.wl_en_driver.num_stages
+        
+    def get_num_sen_driver_stages(self):
+        """Gets the number of stages in the sen driver from the control logic"""
+        return self.sram.control_logic_rw.s_en_driver.num_stages
+     
+    def get_num_wl_driver_stages(self):
+        """Gets the number of stages in the wordline driver from the control logic"""
+        return self.sram.bank.wordline_driver.inv.num_stages 
+     
+    def scale_delays(self, delay_list):
+        """Takes in a list of measured delays and convert it to simple units to easily compare to model values."""
+        converted_values = []
+        #Calculate average
+        total = 0
+        for meas_value in delay_list:
+            total+=meas_value
+        average = total/len(delay_list)
+        
+        #Convert values
+        for meas_value in delay_list:
+            converted_values.append(meas_value/average)
+        return converted_values
+    
+    def min_max_normalization(self, value_list):
+        """Re-scales input values on a range from 0-1 where min(list)=0, max(list)=1"""
+        scaled_values = []
+        min_max_diff = max(value_list) - min(value_list)
+        average = sum(value_list)/len(value_list)
+        for value in value_list:
+            scaled_values.append((value-average)/(min_max_diff))
+        return scaled_values
+        
+    def calculate_error_l2_norm(self, list_a, list_b):    
+        """Calculates error between two lists using the l2 norm"""
+        error_list = []
+        for val_a, val_b in zip(list_a, list_b):
+            error_list.append((val_a-val_b)**2)
+        return error_list
+    
+    def compare_measured_and_model(self, measured_vals, model_vals):
+        """First scales both inputs into similar ranges and then compares the error between both."""
+        scaled_meas = self.min_max_normalization(measured_vals)
+        debug.info(1, "Scaled measurements:\n{}".format(scaled_meas))
+        scaled_model = self.min_max_normalization(model_vals)
+        debug.info(1, "Scaled model:\n{}".format(scaled_model))
+        errors = self.calculate_error_l2_norm(scaled_meas, scaled_model)
+        debug.info(1, "Errors:\n{}\n".format(errors))
+        
+    def analyze(self, probe_address, probe_data, slews, loads):
+        """Measures entire delay path along the wordline and sense amp enable and compare it to the model delays."""
+        self.load=max(loads)
+        self.slew=max(slews)
+        self.set_probe(probe_address, probe_data)
+        self.create_signal_names()
+        self.create_measurement_names()
+        self.create_measurement_objects()
+        data_dict = {}
+        
+        read_port = self.read_ports[0] #only test the first read port
+        self.targ_read_ports = [read_port]
+        self.targ_write_ports = [self.write_ports[0]]
+        debug.info(1,"Model test: corner {}".format(self.corner))
+        (success, wl_delays, sae_delays, wl_slews, sae_slews)=self.run_delay_simulation()
+        debug.check(success, "Model measurements Failed: period={}".format(self.period))
+        wl_model_delays, sae_model_delays = self.get_model_delays(read_port)
+        
+        debug.info(1,"Measured Wordline delays (ns):\n\t {}".format(wl_delays[read_port]))
+        debug.info(1,"Wordline model delays:\n\t {}".format(wl_model_delays))
+        debug.info(1,"Measured Wordline slews:\n\t {}".format(wl_slews[read_port]))
+        debug.info(1,"Measured SAE delays (ns):\n\t {}".format(sae_delays[read_port]))
+        debug.info(1,"SAE model delays:\n\t {}".format(sae_model_delays))
+        debug.info(1,"Measured SAE slews:\n\t {}".format(sae_slews[read_port]))
+        
+        data_dict[self.wl_meas_name] = wl_delays[read_port]
+        data_dict[self.wl_model_name] = wl_model_delays
+        data_dict[self.sae_meas_name] = sae_delays[read_port]
+        data_dict[self.sae_model_name] = sae_model_delays
+        
+        #Some evaluations of the model and measured values
+        debug.info(1, "Comparing wordline measurements and model.")
+        self.compare_measured_and_model(wl_delays[read_port], wl_model_delays)
+        debug.info(1, "Comparing SAE measurements and model")
+        self.compare_measured_and_model(sae_delays[read_port], sae_model_delays)
+        
+        return data_dict
+
+    def get_all_signal_names(self):
+        """Returns all signals names as a dict indexed by hardcoded names. Useful for writing the head of the CSV."""
+        name_dict = {}
+        #Signal names are more descriptive than the measurement names, first value trimmed to match size of measurements names.
+        name_dict[self.wl_meas_name] = self.wl_signal_names[1:]
+        name_dict[self.wl_model_name] = name_dict["wl_measures"] #model uses same names as measured.
+        name_dict[self.sae_meas_name] = self.rbl_en_signal_names[1:]+self.sae_signal_names[1:]
+        name_dict[self.sae_model_name] = name_dict["sae_measures"]
+        return name_dict
+    
+    
+  
\ No newline at end of file
diff --git a/compiler/modules/control_logic.py b/compiler/modules/control_logic.py
index d4597cf9..57e578f5 100644
--- a/compiler/modules/control_logic.py
+++ b/compiler/modules/control_logic.py
@@ -30,13 +30,15 @@ class control_logic(design.design):
         self.port_type = port_type
 
         self.num_cols = word_size*words_per_row
-        self.num_words = num_rows * words_per_row
+        self.num_words = num_rows*words_per_row
         
-        self.enable_delay_chain_resizing = False
+        self.enable_delay_chain_resizing = True
         
-        #self.sram=None #disable re-sizing for debugging, FIXME: resizing is not working, needs to be adjusted for new control logic.
-        self.wl_timing_tolerance = 1 #Determines how much larger the sen delay should be. Accounts for possible error in model.
-        self.parasitic_inv_delay = parameter["min_inv_para_delay"] #Keeping 0 for now until further testing.
+        #Determines how much larger the sen delay should be. Accounts for possible error in model.
+        self.wl_timing_tolerance = 1 
+        self.parasitic_inv_delay = parameter["min_inv_para_delay"] 
+        self.wl_stage_efforts = None
+        self.sen_stage_efforts = None
         
         if self.port_type == "rw":
             self.num_control_signals = 2
@@ -130,43 +132,62 @@ class control_logic(design.design):
         self.add_mod(self.p_en_bar_driver)
         
         if (self.port_type == "rw") or (self.port_type == "r"):
-            delay_stages_heuristic, delay_fanout_heuristic = self.get_heuristic_delay_chain_size()
-            bitcell_loads = int(math.ceil(self.num_rows / 2.0))
-            self.replica_bitline = factory.create(module_type="replica_bitline",
-                                                  delay_fanout_list=[delay_fanout_heuristic]*delay_stages_heuristic,
-                                                  bitcell_loads=bitcell_loads)
-
-            
-            if self.sram != None:
-                self.set_sen_wl_delays()
-            
-            if self.sram != None and self.enable_delay_chain_resizing and not self.does_sen_total_timing_match(): #check condition based on resizing method
-                #This resizes to match fall and rise delays, can make the delay chain weird sizes.
-                # stage_list = self.get_dynamic_delay_fanout_list(delay_stages_heuristic, delay_fanout_heuristic)
-                # self.replica_bitline = replica_bitline(stage_list, bitcell_loads, name="replica_bitline_resized_"+self.port_type)
-                
-                #This resizes based on total delay. 
-                delay_stages, delay_fanout = self.get_dynamic_delay_chain_size(delay_stages_heuristic, delay_fanout_heuristic)
+            from importlib import reload
+            self.delay_chain_resized = False
+            c = reload(__import__(OPTS.replica_bitline))
+            replica_bitline = getattr(c, OPTS.replica_bitline)
+            bitcell_loads = int(math.ceil(self.num_rows * parameter["rbl_height_percentage"]))
+            #Use a model to determine the delays with that heuristic
+            if OPTS.use_tech_delay_chain_size: #Use tech parameters if set.
+                delay_stages =  parameter["static_delay_stages"]
+                delay_fanout = parameter["static_fanout_per_stage"]
+                debug.info(1, "Using tech parameters to size delay chain: stages={}, fanout={}".format(delay_stages,delay_fanout))
                 self.replica_bitline = factory.create(module_type="replica_bitline",
                                                       delay_fanout_list=[delay_fanout]*delay_stages,
                                                       bitcell_loads=bitcell_loads)
-
-                self.sen_delay_rise,self.sen_delay_fall = self.get_delays_to_sen() #get the new timing
+                if self.sram != None: #Calculate model value even for specified sizes
+                    self.set_sen_wl_delays()
+                
+            else: #Otherwise, use a heuristic and/or model based sizing.
+                #First use a heuristic
+                delay_stages_heuristic, delay_fanout_heuristic = self.get_heuristic_delay_chain_size()
+                self.replica_bitline = factory.create(module_type="replica_bitline",
+                                                      delay_fanout_list=[delay_fanout_heuristic]*delay_stages_heuristic,
+                                                      bitcell_loads=bitcell_loads)
+                #Resize if necessary, condition depends on resizing method
+                if self.sram != None and self.enable_delay_chain_resizing and not self.does_sen_rise_fall_timing_match(): 
+                    #This resizes to match fall and rise delays, can make the delay chain weird sizes.
+                    stage_list = self.get_dynamic_delay_fanout_list(delay_stages_heuristic, delay_fanout_heuristic)
+                    self.replica_bitline = factory.create(module_type="replica_bitline",
+                                                          delay_fanout_list=stage_list,
+                                                          bitcell_loads=bitcell_loads)
+                    
+                    #This resizes based on total delay. 
+                    # delay_stages, delay_fanout = self.get_dynamic_delay_chain_size(delay_stages_heuristic, delay_fanout_heuristic)
+                    # self.replica_bitline = factory.create(module_type="replica_bitline",
+                                                          # delay_fanout_list=[delay_fanout]*delay_stages,
+                                                          # bitcell_loads=bitcell_loads)
+                    
+                    self.sen_delay_rise,self.sen_delay_fall = self.get_delays_to_sen() #get the new timing
+                    self.delay_chain_resized = True
                 
             self.add_mod(self.replica_bitline)
 
     def get_heuristic_delay_chain_size(self):
         """Use a basic heuristic to determine the size of the delay chain used for the Sense Amp Enable """
-        # FIXME: These should be tuned according to the additional size parameters
-        delay_fanout = 3 # This can be anything >=2
-        # Delay stages Must be non-inverting
-        if self.words_per_row >= 4:
+        #FIXME: The minimum was 2 fanout, now it will not pass DRC unless it is 3. Why?
+        delay_fanout = 3 # This can be anything >=3
+        # Model poorly captures delay of the column mux. Be pessismistic for column mux
+        if self.words_per_row >= 2:
             delay_stages = 8
-        elif self.words_per_row == 2:
-            delay_stages = 6
         else:
-            delay_stages = 4
-            
+            delay_stages = 2
+        
+        #Read ports have a shorter s_en delay. The model is not accurate enough to catch this difference
+        #on certain sram configs.
+        if self.port_type == "r":
+            delay_stages+=2
+        
         return (delay_stages, delay_fanout)
         
     def set_sen_wl_delays(self):
@@ -227,14 +248,25 @@ class control_logic(design.design):
         required_delay_rise = self.wl_delay_rise*self.wl_timing_tolerance - (self.sen_delay_rise-previous_delay_chain_delay/2)
         debug.info(2,"Required delays from chain: fall={}, rise={}".format(required_delay_fall,required_delay_rise))
         
+        #If the fanout is different between rise/fall by this amount. Stage algorithm is made more pessimistic.
+        WARNING_FANOUT_DIFF = 5
+        stages_close = False
         #The stages need to be equal (or at least a even number of stages with matching rise/fall delays)
         while True:
             stages_fall = self.calculate_stages_with_fixed_fanout(required_delay_fall,fanout_fall)
             stages_rise = self.calculate_stages_with_fixed_fanout(required_delay_rise,fanout_rise)
             debug.info(1,"Fall stages={}, rise stages={}".format(stages_fall,stages_rise))
+            if abs(stages_fall-stages_rise) == 1 and not stages_close:
+                stages_close = True
+                safe_fanout_rise = fanout_rise
+                safe_fanout_fall = fanout_fall
+            
             if stages_fall == stages_rise: 
                 break
-            elif abs(stages_fall-stages_rise) == 1:
+            elif abs(stages_fall-stages_rise) == 1 and WARNING_FANOUT_DIFF < abs(fanout_fall-fanout_rise):
+                debug.info(1, "Delay chain fanouts between stages are large. Making chain size larger for safety.")
+                fanout_rise = safe_fanout_rise
+                fanout_fall = safe_fanout_fall
                 break
             #There should also be a condition to make sure the fanout does not get too large.    
             #Otherwise, increase the fanout of delay with the most stages, calculate new stages
@@ -819,8 +851,8 @@ class control_logic(design.design):
     def get_delays_to_wl(self):
         """Get the delay (in delay units) of the clk to a wordline in the bitcell array"""
         debug.check(self.sram.all_mods_except_control_done, "Cannot calculate sense amp enable delay unless all module have been added.")
-        stage_efforts = self.determine_wordline_stage_efforts()
-        clk_to_wl_rise,clk_to_wl_fall = logical_effort.calculate_relative_rise_fall_delays(stage_efforts, self.parasitic_inv_delay)
+        self.wl_stage_efforts = self.determine_wordline_stage_efforts()
+        clk_to_wl_rise,clk_to_wl_fall = logical_effort.calculate_relative_rise_fall_delays(self.wl_stage_efforts, self.parasitic_inv_delay)
         total_delay = clk_to_wl_rise + clk_to_wl_fall 
         debug.info(1, "Clock to wl delay is rise={:.3f}, fall={:.3f}, total={:.3f} in delay units".format(clk_to_wl_rise, clk_to_wl_fall,total_delay))
         return clk_to_wl_rise,clk_to_wl_fall 
@@ -849,8 +881,8 @@ class control_logic(design.design):
            This does not incorporate the delay of the replica bitline.
         """
         debug.check(self.sram.all_mods_except_control_done, "Cannot calculate sense amp enable delay unless all module have been added.")
-        stage_efforts = self.determine_sa_enable_stage_efforts()
-        clk_to_sen_rise, clk_to_sen_fall = logical_effort.calculate_relative_rise_fall_delays(stage_efforts, self.parasitic_inv_delay)
+        self.sen_stage_efforts = self.determine_sa_enable_stage_efforts()
+        clk_to_sen_rise, clk_to_sen_fall = logical_effort.calculate_relative_rise_fall_delays(self.sen_stage_efforts, self.parasitic_inv_delay)
         total_delay = clk_to_sen_rise + clk_to_sen_fall 
         debug.info(1, "Clock to s_en delay is rise={:.3f}, fall={:.3f}, total={:.3f} in delay units".format(clk_to_sen_rise, clk_to_sen_fall,total_delay))
         return clk_to_sen_rise, clk_to_sen_fall   
@@ -881,4 +913,12 @@ class control_logic(design.design):
         last_stage_rise = stage_effort_list[-1].is_rise
         
         return stage_effort_list    
-       
+
+    def get_wl_sen_delays(self):
+        """Gets a list of the stages and delays in order of their path."""
+        if self.sen_stage_efforts == None or self.wl_stage_efforts == None:
+            debug.error("Model delays not calculated for SRAM.", 1)
+        wl_delays = logical_effort.calculate_delays(self.wl_stage_efforts, self.parasitic_inv_delay)
+        sen_delays = logical_effort.calculate_delays(self.sen_stage_efforts, self.parasitic_inv_delay)
+        return wl_delays, sen_delays
+        
diff --git a/compiler/modules/sense_amp.py b/compiler/modules/sense_amp.py
index 8553e42c..9601259c 100644
--- a/compiler/modules/sense_amp.py
+++ b/compiler/modules/sense_amp.py
@@ -48,4 +48,5 @@ class sense_amp(design.design):
         """Get the relative capacitance of sense amp enable gate cin"""
         pmos_cin = parameter["sa_en_pmos_size"]/drc("minwidth_tx")
         nmos_cin = parameter["sa_en_nmos_size"]/drc("minwidth_tx")
+        #sen is connected to 2 pmos isolation TX and 1 nmos per sense amp.
         return 2*pmos_cin + nmos_cin
\ No newline at end of file
diff --git a/compiler/modules/sense_amp_array.py b/compiler/modules/sense_amp_array.py
index ebf95c95..dc80a13b 100644
--- a/compiler/modules/sense_amp_array.py
+++ b/compiler/modules/sense_amp_array.py
@@ -142,4 +142,4 @@ class sense_amp_array(design.design):
     def get_en_cin(self):
         """Get the relative capacitance of all the sense amp enable connections in the array"""
         sense_amp_en_cin = self.amp.get_en_cin()
-        return sense_amp_en_cin * self.words_per_row
+        return sense_amp_en_cin * self.word_size
diff --git a/compiler/options.py b/compiler/options.py
index fc1eb7d1..4d3461e6 100644
--- a/compiler/options.py
+++ b/compiler/options.py
@@ -71,6 +71,9 @@ class options(optparse.Values):
     # You can manually specify banks, but it is better to auto-detect it.
     num_banks = 1
     
+    #Uses the delay chain size in the tech.py file rather automatic sizing.
+    use_tech_delay_chain_size = False
+    
     # These are the default modules that can be over-riden
     bank_select = "bank_select"
     bitcell_array = "bitcell_array"
diff --git a/compiler/pgates/pdriver.py b/compiler/pgates/pdriver.py
index 3a0e4e78..23f3f4f8 100644
--- a/compiler/pgates/pdriver.py
+++ b/compiler/pgates/pdriver.py
@@ -196,17 +196,16 @@ class pdriver(pgate.pgate):
 
     def get_stage_efforts(self, external_cout, inp_is_rise=False):
         """Get the stage efforts of the A -> Z path"""
-
-        cout_list = {}
+        cout_list = []
         for prev_inv,inv in zip(self.inv_list, self.inv_list[1:]):
-            cout_list[prev_inv]=inv.get_cin()
-            
-        cout_list[self.inv_list[-1]]=external_cout
+            cout_list.append(inv.get_cin())
+        
+        cout_list.append(external_cout)
         
         stage_effort_list = []
         last_inp_is_rise = inp_is_rise
-        for inv in self.inv_list:
-            stage = inv.get_stage_effort(cout_list[inv], last_inp_is_rise)
+        for inv,cout in zip(self.inv_list,cout_list):
+            stage = inv.get_stage_effort(cout, last_inp_is_rise)
             stage_effort_list.append(stage)
             last_inp_is_rise = stage.is_rise
             
diff --git a/compiler/pgates/pinv.py b/compiler/pgates/pinv.py
index aa16ab54..f1ba89f4 100644
--- a/compiler/pgates/pinv.py
+++ b/compiler/pgates/pinv.py
@@ -292,4 +292,4 @@ class pinv(pgate.pgate):
            Optional is_rise refers to the input direction rise/fall. Input inverted by this stage.
         """
         parasitic_delay = 1 
-        return logical_effort.logical_effort(self.size, self.get_cin(), cout, parasitic_delay, not inp_is_rise)
+        return logical_effort.logical_effort(self.name, self.size, self.get_cin(), cout, parasitic_delay, not inp_is_rise)
diff --git a/compiler/pgates/pnand2.py b/compiler/pgates/pnand2.py
index d196bf15..fa24dc1f 100644
--- a/compiler/pgates/pnand2.py
+++ b/compiler/pgates/pnand2.py
@@ -258,4 +258,4 @@ class pnand2(pgate.pgate):
            Optional is_rise refers to the input direction rise/fall. Input inverted by this stage.
         """
         parasitic_delay = 2 
-        return logical_effort.logical_effort(self.size, self.get_cin(), cout, parasitic_delay, not inp_is_rise)
+        return logical_effort.logical_effort(self.name, self.size, self.get_cin(), cout, parasitic_delay, not inp_is_rise)
diff --git a/compiler/pgates/pnand3.py b/compiler/pgates/pnand3.py
index 29ae98c0..d4554863 100644
--- a/compiler/pgates/pnand3.py
+++ b/compiler/pgates/pnand3.py
@@ -4,6 +4,7 @@ import debug
 from tech import drc, parameter, spice
 from vector import vector
 from globals import OPTS
+import logical_effort
 from sram_factory import factory
 
 class pnand3(pgate.pgate):
@@ -270,4 +271,4 @@ class pnand3(pgate.pgate):
            Optional is_rise refers to the input direction rise/fall. Input inverted by this stage.
         """
         parasitic_delay = 3 
-        return logical_effort.logical_effort(self.size, self.get_cin(), cout, parasitic_delay, not inp_is_rise)
+        return logical_effort.logical_effort(self.name, self.size, self.get_cin(), cout, parasitic_delay, not inp_is_rise)
diff --git a/compiler/sram_config.py b/compiler/sram_config.py
index 24e3cbc9..5edf9282 100644
--- a/compiler/sram_config.py
+++ b/compiler/sram_config.py
@@ -7,13 +7,13 @@ from sram_factory import factory
 class sram_config:
     """ This is a structure that is used to hold the SRAM configuration options. """
     
-    def __init__(self, word_size, num_words, num_banks=1):
+    def __init__(self, word_size, num_words, num_banks=1, words_per_row=None):
         self.word_size = word_size
         self.num_words = num_words
         self.num_banks = num_banks
 
         # This will get over-written when we determine the organization
-        self.words_per_row = None
+        self.words_per_row = words_per_row
 
         self.compute_sizes()
         
diff --git a/compiler/tests/16_control_logic_test.py b/compiler/tests/16_control_logic_test.py
index 91ad0500..e0545af4 100755
--- a/compiler/tests/16_control_logic_test.py
+++ b/compiler/tests/16_control_logic_test.py
@@ -36,17 +36,21 @@ class control_logic_test(openram_test):
         
         # Check port specific control logic
         OPTS.num_rw_ports = 1
-        OPTS.num_w_ports = 1
-        OPTS.num_r_ports = 1
+        OPTS.num_w_ports = 0
+        OPTS.num_r_ports = 0
 
         debug.info(1, "Testing sample for control_logic for multiport, only write control logic")
         a = control_logic.control_logic(num_rows=128, words_per_row=1, word_size=8, port_type="rw")
         self.local_check(a)
         
+        OPTS.num_rw_ports = 0
+        OPTS.num_w_ports = 1
         debug.info(1, "Testing sample for control_logic for multiport, only write control logic")
         a = control_logic.control_logic(num_rows=128, words_per_row=1, word_size=8, port_type="w")
         self.local_check(a)
         
+        OPTS.num_w_ports = 0
+        OPTS.num_r_ports = 1
         debug.info(1, "Testing sample for control_logic for multiport, only read control logic")
         a = control_logic.control_logic(num_rows=128, words_per_row=1, word_size=8, port_type="r")
         self.local_check(a)
diff --git a/compiler/tests/21_hspice_delay_test.py b/compiler/tests/21_hspice_delay_test.py
index d412d42f..fa7fc35f 100755
--- a/compiler/tests/21_hspice_delay_test.py
+++ b/compiler/tests/21_hspice_delay_test.py
@@ -23,7 +23,7 @@ class timing_sram_test(openram_test):
         from importlib import reload
         import characterizer
         reload(characterizer)
-        from characterizer import delay, bitline_delay
+        from characterizer import delay
         from sram import sram
         from sram_config import sram_config
         c = sram_config(word_size=1,
@@ -43,37 +43,44 @@ class timing_sram_test(openram_test):
 
         corner = (OPTS.process_corners[0], OPTS.supply_voltages[0], OPTS.temperatures[0])
         d = delay(s.s, tempspice, corner)
-        bl = bitline_delay(s.s, tempspice, corner)
         import tech
         loads = [tech.spice["msflop_in_cap"]*4]
         slews = [tech.spice["rise_time"]*2]
         data, port_data = d.analyze(probe_address, probe_data, slews, loads)
-        #bitline_swing = bl.analyze(probe_address, probe_data, slews, loads)
         #Combine info about port into all data
         data.update(port_data[0])
-        
+     
         if OPTS.tech_name == "freepdk45":
-            golden_data = {'delay_hl': [0.2152017],
-                           'delay_lh': [0.2152017],
-                           'leakage_power': 0.0022907,
-                           'min_period': 0.488,
-                           'read0_power': [0.47437749999999995],
-                           'read1_power': [0.45026109999999997],
-                           'slew_hl': [0.0846786],
-                           'slew_lh': [0.0846786],
-                           'write0_power': [0.40809259999999997],
-                           'write1_power': [0.4078904]}
+            golden_data = {'delay_bl': [0.1980959],
+                         'delay_br': [0.1946091],
+                         'delay_hl': [0.2121267],
+                         'delay_lh': [0.2121267],
+                         'leakage_power': 0.0023761999999999998,
+                         'min_period': 0.43,
+                         'read0_power': [0.5139368],
+                         'read1_power': [0.48940979999999995],
+                         'slew_hl': [0.0516745],
+                         'slew_lh': [0.0516745],
+                         'volt_bl': [0.5374525],
+                         'volt_br': [1.1058],
+                         'write0_power': [0.46267169999999996],
+                         'write1_power': [0.4670826]}
         elif OPTS.tech_name == "scn4m_subm":
-            golden_data = {'delay_hl': [1.4333000000000002],
-                           'delay_lh': [1.4333000000000002],
-                           'leakage_power': 0.0271847,
-                           'min_period': 2.891,
-                           'read0_power': [15.714200000000002],
-                           'read1_power': [14.9848],
-                           'slew_hl': [0.6819276999999999],
-                           'slew_lh': [0.6819276999999999],
-                           'write0_power': [13.9658],
-                           'write1_power': [14.8422]}
+            golden_data = {'delay_bl': [1.1029],
+                         'delay_br': [0.9656455999999999],
+                         'delay_hl': [1.288],
+                         'delay_lh': [1.288],
+                         'leakage_power': 0.0273896,
+                         'min_period': 2.578,
+                         'read0_power': [16.9996],
+                         'read1_power': [16.2616],
+                         'slew_hl': [0.47891700000000004],
+                         'slew_lh': [0.47891700000000004],
+                         'volt_bl': [4.2155],
+                         'volt_br': [5.8142],
+                         'write0_power': [16.0656],
+                         'write1_power': [16.2616]}
+
         else:
             self.assertTrue(False) # other techs fail
         # Check if no too many or too few results
diff --git a/compiler/tests/21_ngspice_delay_test.py b/compiler/tests/21_ngspice_delay_test.py
index aac42fa6..5af44e69 100755
--- a/compiler/tests/21_ngspice_delay_test.py
+++ b/compiler/tests/21_ngspice_delay_test.py
@@ -51,27 +51,36 @@ class timing_sram_test(openram_test):
         data.update(port_data[0])
 
         if OPTS.tech_name == "freepdk45":
-            golden_data = {'delay_hl': [0.221699],
-                           'delay_lh': [0.221699],
-                           'leakage_power': 0.001467648,
-                           'min_period': 0.605,
-                           'read0_power': [0.3879335],
-                           'read1_power': [0.3662724],
-                           'slew_hl': [0.08562444999999999],
-                           'slew_lh': [0.08562444999999999],
-                           'write0_power': [0.3362456],
-                           'write1_power': [0.3372035]}
+            golden_data = {'delay_bl': [0.2003652],
+                         'delay_br': [0.198698],
+                         'delay_hl': [0.2108836],
+                         'delay_lh': [0.2108836],
+                         'leakage_power': 0.001564799,
+                         'min_period': 0.508,
+                         'read0_power': [0.43916689999999997],
+                         'read1_power': [0.4198608],
+                         'slew_hl': [0.0455126],
+                         'slew_lh': [0.0455126],
+                         'volt_bl': [0.6472883],
+                         'volt_br': [1.114024],
+                         'write0_power': [0.40681890000000004],
+                         'write1_power': [0.4198608]}
         elif OPTS.tech_name == "scn4m_subm":
-            golden_data = {'delay_hl': [1.7951730000000001],
-                           'delay_lh': [1.7951730000000001],
-                           'leakage_power': 0.001669513,
-                           'min_period': 3.594,
-                           'read0_power': [17.03022],
-                           'read1_power': [16.55897],
-                           'slew_hl': [0.7079951],
-                           'slew_lh': [0.7079951],
-                           'write0_power': [15.16726],
-                           'write1_power': [16.13527]}
+            golden_data = {'delay_bl': [1.3937359999999999],
+                         'delay_br': [1.2596429999999998],
+                         'delay_hl': [1.5747600000000002],
+                         'delay_lh': [1.5747600000000002],
+                         'leakage_power': 0.00195795,
+                         'min_period': 3.281,
+                         'read0_power': [14.92874],
+                         'read1_power': [14.369810000000001],
+                         'slew_hl': [0.49631959999999997],
+                         'slew_lh': [0.49631959999999997],
+                         'volt_bl': [4.132618],
+                         'volt_br': [5.573099],
+                         'write0_power': [13.79953],
+                         'write1_power': [14.369810000000001]}
+
         else:
             self.assertTrue(False) # other techs fail
 
diff --git a/compiler/tests/28_delay_model_test.py b/compiler/tests/28_delay_model_test.py
new file mode 100755
index 00000000..a02a42e9
--- /dev/null
+++ b/compiler/tests/28_delay_model_test.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+"""
+Run a regression test on various srams
+"""
+
+import unittest
+from testutils import header,openram_test
+import sys,os
+sys.path.append(os.path.join(sys.path[0],".."))
+import globals
+from globals import OPTS
+import debug
+
+class delay_model_test(openram_test):
+
+    def runTest(self):
+        globals.init_openram("config_20_{0}".format(OPTS.tech_name))
+        OPTS.spice_name="hspice"
+        OPTS.analytical_delay = False
+        OPTS.netlist_only = True
+        OPTS.trim_netlist = False
+        debug.info(1, "Trimming disabled for this test. Simulation could be slow.")
+        
+        # This is a hack to reload the characterizer __init__ with the spice version
+        from importlib import reload
+        import characterizer
+        reload(characterizer)
+        
+        from characterizer import model_check
+        from sram import sram
+        from sram_config import sram_config
+        c = sram_config(word_size=4,
+                        num_words=16,
+                        num_banks=1)
+        c.words_per_row=1
+        c.recompute_sizes()
+        debug.info(1, "Testing timing for sample 1bit, 16words SRAM with 1 bank")
+        s = sram(c, name="sram1")
+
+        tempspice = OPTS.openram_temp + "temp.sp"
+        s.sp_write(tempspice)
+
+        probe_address = "1" * s.s.addr_size
+        probe_data = s.s.word_size - 1
+        debug.info(1, "Probe address {0} probe data bit {1}".format(probe_address, probe_data))
+
+        corner = (OPTS.process_corners[0], OPTS.supply_voltages[0], OPTS.temperatures[0])
+        mc = model_check(s.s, tempspice, corner)
+        import tech
+        loads = [tech.spice["msflop_in_cap"]*4]
+        slews = [tech.spice["rise_time"]*2]
+        sram_data = mc.analyze(probe_address, probe_data, slews, loads)
+        #Combine info about port into all data
+
+        #debug.info(1,"Data:\n{}".format(wl_data))
+
+        globals.end_openram()
+        
+# run the test from the command line
+if __name__ == "__main__":
+    (OPTS, args) = globals.parse_args()
+    del sys.argv[1:]
+    header(__file__, OPTS.tech_name)
+    unittest.main()
diff --git a/compiler/tests/config_data.py b/compiler/tests/config_data.py
new file mode 100755
index 00000000..849d441d
--- /dev/null
+++ b/compiler/tests/config_data.py
@@ -0,0 +1,11 @@
+#Config file used for collecting data.
+word_size = 1
+num_words = 16
+
+tech_name = "freepdk45"
+#process_corners = ["TT", "FF", "SS", "SF", "FS"]
+process_corners = ["TT", "FF", "SS"]
+supply_voltages = [1.0]
+temperatures = [25]
+
+
diff --git a/compiler/tests/delay_data_collection.py b/compiler/tests/delay_data_collection.py
new file mode 100644
index 00000000..e893d8ec
--- /dev/null
+++ b/compiler/tests/delay_data_collection.py
@@ -0,0 +1,384 @@
+#!/usr/bin/env python3
+"""
+Run a regression test on various srams
+"""
+import csv,sys,os
+import pandas as pd
+import matplotlib.pyplot as plt
+
+import unittest
+from testutils import header,openram_test
+sys.path.append(os.path.join(sys.path[0],".."))
+import globals
+from globals import OPTS
+import debug
+from sram import sram
+from sram_config import sram_config
+
+MODEL_DIR = "model_data/"
+
+class data_collection(openram_test):
+
+    def runTest(self):
+    
+        #Uncomment this for model evaluation
+        # ratio_data = self.calculate_delay_ratios_of_srams()
+        # self.display_data(ratio_data)
+
+        self.run_delay_chain_analysis()
+        
+        globals.end_openram()
+    
+    def run_delay_chain_analysis(self):
+        """Generates sram with different delay chain configs over different corners and 
+           analyzes delay average and variation."""
+        OPTS.use_tech_delay_chain_size = True
+        #Constant sram config for this test   
+        word_size, num_words, words_per_row = 1, 16, 1
+        #Only change delay chain
+        dc_config_list = [(2,3), (3,3), (3,4), (4,2), (4,3), (4,4), (2,4), (2,5)]
+        #dc_config_list = [(2,3), (3,3)]
+        dc_avgs = []
+        dc_vars = []
+        for stages,fanout in dc_config_list:
+            self.init_data_gen()
+            self.set_delay_chain(stages,fanout)
+            self.save_data_sram_corners(word_size, num_words, words_per_row)
+            wl_dataframe, sae_dataframe = self.get_csv_data()
+            delay_sums = self.get_delay_chain_sums(sae_dataframe)
+            dc_avgs.append(self.get_average(delay_sums))
+            dc_vars.append(self.get_variance(delay_sums))
+            debug.info(1,"DC config={}: avg={} variance={}".format((stages,fanout), dc_avgs[-1], dc_vars[-1]))
+        
+        #plot data
+        self.plot_two_data_sets(dc_config_list, dc_avgs, dc_vars)
+        #self.plot_data(dc_config_list, dc_avgs)
+        #self.plot_data(dc_config_list, dc_vars)
+    
+    def get_delay_chain_sums(self, sae_dataframe):
+        """Calculate the total delay of the delay chain over different corners"""
+        (start_dc, end_dc) = self.delay_obj.delay_chain_indices
+        start_data_pos = len(self.config_fields)+1 #items before this point are configuration related
+        delay_sums = []
+        row_count = 0
+        #Get delay sums over different corners
+        for sae_row in sae_dataframe.itertuples(): 
+            dc_delays = sae_row[start_data_pos+start_dc:start_data_pos+end_dc]
+            delay_sums.append(sum(dc_delays))
+        return delay_sums
+        
+    def get_variance(self, nums):
+        avg = self.get_average(nums)
+        delay_variance = sum((xi - avg) ** 2 for xi in nums) / len(nums)
+        return delay_variance
+        
+    def get_average(self,nums):
+        return sum(nums) / len(nums)
+    
+    def plot_data(self, x_labels, y_values):
+        """Display a plot using matplot lib. 
+           Assumes input x values are just labels and y values are actual data."""
+        data_range = [i+1 for i in range(len(x_labels))]
+        plt.xticks(data_range, x_labels)
+        plt.plot(data_range, y_values, 'ro')
+        plt.show()
+    
+    def plot_two_data_sets(self, x_labels, y1_values, y2_values):
+        """Plots two data sets on the same x-axis."""
+        data_range = [i for i in range(len(x_labels))]
+        fig, ax1 = plt.subplots()
+
+        color = 'tab:red'
+        ax1.set_xlabel('DC (Stages,Fanout)')
+        ax1.set_ylabel('Average Delay (ns)', color=color)
+        ax1.plot(data_range, y1_values, marker='o', color=color, linestyle='')
+        ax1.tick_params(axis='y', labelcolor=color)
+
+        ax2 = ax1.twinx()  # instantiate a second axes that shares the same x-axis
+
+        color = 'tab:blue'
+        #ax2.set_xticks(data_range, x_labels)
+        ax2.set_ylabel('Delay Variance (ns)', color=color)  # we already handled the x-label with ax1
+        ax2.plot(data_range, y2_values, marker='*', color=color, linestyle='')
+        ax2.tick_params(axis='y', labelcolor=color)
+
+        fig.tight_layout()  # otherwise the right y-label is slightly clipped
+        plt.xticks(data_range, x_labels)
+        plt.show()
+    
+    def calculate_delay_ratios_of_srams(self):
+        """Runs delay measurements on several sram configurations.
+        Computes the delay ratio for each one."""
+        delay_ratio_data = {}
+        config_tuple_list = [(32, 1024, None)]
+        #config_tuple_list = [(1, 16, 1),(4, 16, 1), (16, 16, 1), (32, 32, 1)]
+        for sram_config in config_tuple_list:
+            word_size, num_words, words_per_row = sram_config
+            self.init_data_gen()
+            self.save_data_sram_corners(word_size, num_words, words_per_row)
+            model_delay_ratios, meas_delay_ratios, ratio_error = self.compare_model_to_measure()
+            delay_ratio_data[sram_config] = ratio_error
+            debug.info(1, "Ratio percentage error={}".format(ratio_error))
+        return delay_ratio_data
+        
+    def get_csv_data(self):
+        """Hardcoded Hack to get the measurement data from the csv into lists. """
+        wl_files_name = [file_name for file_name in self.file_names if "wl_measures" in file_name][0]
+        sae_files_name = [file_name for file_name in self.file_names if "sae_measures" in file_name][0]
+        wl_dataframe = pd.read_csv(wl_files_name,encoding='utf-8')
+        sae_dataframe = pd.read_csv(sae_files_name,encoding='utf-8')
+        return wl_dataframe,sae_dataframe 
+        
+    def evaluate_data(self, wl_dataframe, sae_dataframe):
+        """Analyze the delay error and variation error"""
+        delay_error = self.calculate_delay_error(wl_dataframe, sae_dataframe)
+        debug.info(1, "Delay errors:{}".format(delay_error))
+        variation_error = self.calculate_delay_variation_error(wl_dataframe, sae_dataframe)
+        debug.info(1, "Variation errors:{}".format(variation_error))
+    
+    def compare_model_to_measure(self):
+        """Uses the last 4 recent data sets (wl_meas, sen_meas, wl_model, sen_model)
+           and compare the wl-sen delay ratio between model and measured.
+        """
+        model_delay_ratios = {}
+        meas_delay_ratios = {}
+        ratio_error = {}
+        #The full file name contains unrelated portions, separate them into the four that are needed
+        wl_meas_df = [pd.read_csv(file_name,encoding='utf-8') for file_name in self.file_names if "wl_measures" in file_name][0]
+        sae_meas_df = [pd.read_csv(file_name,encoding='utf-8') for file_name in self.file_names if "sae_measures" in file_name][0]
+        wl_model_df = [pd.read_csv(file_name,encoding='utf-8') for file_name in self.file_names if "wl_model" in file_name][0]
+        sae_model_df = [pd.read_csv(file_name,encoding='utf-8') for file_name in self.file_names if "sae_model" in file_name][0]
+        
+        #Assume each csv has the same corners (and the same row order), use one of the dfs for corners
+        proc_pos, volt_pos, temp_pos = wl_meas_df.columns.get_loc('process'), wl_meas_df.columns.get_loc('voltage'), wl_meas_df.columns.get_loc('temp')
+        wl_sum_pos = wl_meas_df.columns.get_loc('sum')
+        sae_sum_pos = sae_meas_df.columns.get_loc('sum')
+        
+        df_zip = zip(wl_meas_df.itertuples(),sae_meas_df.itertuples(),wl_model_df.itertuples(),sae_model_df.itertuples())
+        for wl_meas,sae_meas,wl_model,sae_model in df_zip:
+            #Use previously calculated position to index the df row. 
+            corner = (wl_meas[proc_pos+1], wl_meas[volt_pos+1], wl_meas[temp_pos+1])
+            meas_delay_ratios[corner] = wl_meas[wl_sum_pos+1]/sae_meas[sae_sum_pos+1]
+            model_delay_ratios[corner] = wl_model[wl_sum_pos+1]/sae_model[sae_sum_pos+1]
+            #Not using absolute error, positive error means model was larger, negative error means it was smaller.
+            ratio_error[corner] = 100*(model_delay_ratios[corner]-meas_delay_ratios[corner])/meas_delay_ratios[corner]
+            
+        return model_delay_ratios, meas_delay_ratios, ratio_error 
+     
+    def display_data(self, data):
+        """Displays the ratio data using matplotlib (requires graphics)"""
+        config_data = []
+        xticks = []
+        #Organize data
+        #First key level if the sram configuration (wordsize, num words, words per row)
+        for config,corner_data_dict in data.items():
+            #Second level is the corner data for that configuration.
+            for corner, corner_data in corner_data_dict.items():
+                #Right now I am only testing with a single corner, will not work with more than 1 corner
+                config_data.append(corner_data)
+            xticks.append("{}b,{}w,{}wpr".format(*config))
+        #plot data
+        data_range = [i+1 for i in range(len(data))]
+        shapes = ['ro', 'bo', 'go', 'co', 'mo']
+        plt.xticks(data_range, xticks)
+        plt.plot(data_range, config_data, 'ro')
+        plt.show()
+        
+    def calculate_delay_error(self, wl_dataframe, sae_dataframe):
+        """Calculates the percentage difference in delays between the wordline and sense amp enable"""
+        start_data_pos = len(self.config_fields) #items before this point are configuration related
+        error_list = []
+        row_count = 0
+        for wl_row, sae_row in zip(wl_dataframe.itertuples(), sae_dataframe.itertuples()):             
+            debug.info(2, "wl_row:{}".format(wl_row))
+            wl_sum = sum(wl_row[start_data_pos+1:])
+            debug.info(2, "wl_sum:{}".format(wl_sum))
+            sae_sum = sum(sae_row[start_data_pos+1:])
+            error_list.append(abs((wl_sum-sae_sum)/wl_sum))
+        return error_list
+        
+    def calculate_delay_variation_error(self, wl_dataframe, sae_dataframe):
+        """Measures a base delay from the first corner then the variations from that base"""
+        start_data_pos = len(self.config_fields)
+        variation_error_list = []
+        count = 0
+        for wl_row, sae_row in zip(wl_dataframe.itertuples(), sae_dataframe.itertuples()):
+            if count == 0:
+                #Create a base delay, variation is defined as the difference between this base
+                wl_base = sum(wl_row[start_data_pos+1:])
+                debug.info(1, "wl_sum base:{}".format(wl_base))
+                sae_base = sum(sae_row[start_data_pos+1:])
+                variation_error_list.append(0.0)
+            else:
+                #Calculate the variation from the respective base and then difference between the variations
+                wl_sum = sum(wl_row[start_data_pos+1:])
+                wl_base_diff = abs((wl_base-wl_sum)/wl_base)
+                sae_sum = sum(sae_row[start_data_pos+1:])
+                sae_base_diff = abs((sae_base-sae_sum)/sae_base)
+                variation_diff = abs((wl_base_diff-sae_base_diff)/wl_base_diff)
+                variation_error_list.append(variation_diff)
+            count+=1
+        return variation_error_list
+        
+    def save_data_sram_corners(self, word_size, num_words, words_per_row):
+        """Performs corner analysis on a single SRAM configuration"""
+        self.create_sram(word_size, num_words, words_per_row)
+        #Setting to none forces SRAM to determine the value. Must be checked after sram creation
+        if not words_per_row: 
+            words_per_row = self.sram.s.words_per_row
+        #Run on one size to initialize CSV writing (csv names come from return value). Strange, but it is okay for now.
+        corner_gen = self.corner_combination_generator()
+        init_corner = next(corner_gen)
+        sram_data = self.get_sram_data(init_corner)
+        dc_resized = self.was_delay_chain_resized()
+        self.initialize_csv_file(word_size, num_words, words_per_row)
+        self.add_sram_data_to_csv(sram_data, word_size, num_words, words_per_row, dc_resized, init_corner) 
+        
+        #Run openRAM for all corners
+        for corner in corner_gen:
+            sram_data = self.get_sram_data(corner)
+            self.add_sram_data_to_csv(sram_data, word_size, num_words, words_per_row, dc_resized, corner)
+            
+        self.close_files()
+        debug.info(1,"Data Generated")
+        
+    def init_data_gen(self):
+        """Initialization for the data test to run"""
+        globals.init_openram("config_data")
+        from tech import parameter
+        global parameter
+        if OPTS.tech_name == "scmos":
+            debug.warning("Device models not up to date with scn4m technology.")
+        OPTS.spice_name="hspice" #Much faster than ngspice.
+        OPTS.trim_netlist = False
+        OPTS.netlist_only = True
+        OPTS.analytical_delay = False
+        #OPTS.use_tech_delay_chain_size = True
+        # This is a hack to reload the characterizer __init__ with the spice version
+        from importlib import reload
+        import characterizer
+        reload(characterizer) 
+
+    def set_delay_chain(self, stages, fanout):
+        """Force change the parameter in the tech file to specify a delay chain configuration"""
+        parameter["static_delay_stages"] = stages
+        parameter["static_fanout_per_stage"] = fanout
+        
+    def close_files(self):
+        """Closes all files stored in the file dict"""
+        for key,file in self.csv_files.items():
+            file.close()
+   
+    def corner_combination_generator(self):
+        processes = OPTS.process_corners
+        voltages = OPTS.supply_voltages
+        temperatures = OPTS.temperatures
+        """Generates corner using a combination of values from config file"""
+        for proc in processes:
+            for volt in voltages:
+                for temp in temperatures:
+                    yield (proc, volt, temp)
+        
+        
+    def get_sram_configs(self):
+        """Generate lists of wordsizes, number of words, and column mux size (words per row) to be tested."""
+        min_word_size = 1
+        max_word_size = 16
+        min_num_words_log2 = 4
+        max_num_words_log2 = 8
+        word_sizes = [i for i in range(min_word_size,max_word_size+1)]
+        num_words = [2**i for i in range(min_num_words_log2,max_num_words_log2+1)]
+        words_per_row = [1]
+        return word_sizes, num_words, words_per_row
+    
+    def add_sram_data_to_csv(self, sram_data, word_size, num_words, words_per_row, dc_resized, corner):
+        """Writes data to its respective CSV file. There is a CSV for each measurement target 
+        (wordline, sense amp enable, and models)"""
+        sram_specs = [word_size,num_words,words_per_row,dc_resized,*corner]
+        for data_name, data_values in sram_data.items():
+            other_values = self.calculate_other_data_values(data_values)
+            self.csv_writers[data_name].writerow(sram_specs+sram_data[data_name]+other_values)
+        debug.info(2,"Data Added to CSV file.")
+    
+    def calculate_other_data_values(self, sram_data_list):
+        """A function to calculate extra values related to the data. Only does the sum for now"""
+        data_sum = sum(sram_data_list)
+        return [data_sum]
+    
+    def initialize_csv_file(self, word_size, num_words, words_per_row):
+        """Opens a CSV file and writer for every data set being written (wl/sae measurements and model values)"""
+        #CSV File writing
+        header_dict = self.delay_obj.get_all_signal_names()
+        self.csv_files = {}
+        self.csv_writers = {}
+        self.file_names = []
+        delay_stages = self.delay_obj.get_num_delay_stages()
+        delay_stage_fanout = self.delay_obj.get_num_delay_stage_fanout()
+        
+        for data_name, header_list in header_dict.items():
+            file_name = '{}data_{}b_{}word_{}way_dc{}x{}_{}.csv'.format(MODEL_DIR,
+                                                                word_size, 
+                                                                num_words, 
+                                                                words_per_row,
+                                                                delay_stages,
+                                                                delay_stage_fanout,
+                                                                data_name)
+            self.file_names.append(file_name)
+            self.csv_files[data_name] = open(file_name, 'w')
+            self.config_fields = ['word_size', 'num_words', 'words_per_row', 'dc_resized', 'process', 'voltage', 'temp']
+            self.other_data_fields = ['sum']
+            fields = (*self.config_fields, *header_list, *self.other_data_fields)
+            self.csv_writers[data_name] = csv.writer(self.csv_files[data_name], lineterminator = '\n')
+            self.csv_writers[data_name].writerow(fields)
+    
+    def create_sram(self, word_size, num_words, words_per_row):
+        """Generates the SRAM based on input configuration."""
+        c = sram_config(word_size=word_size,
+                        num_words=num_words,
+                        num_banks=1,
+                        words_per_row=words_per_row)
+            
+        debug.info(1, "Creating SRAM: {} bit, {} words, with 1 bank".format(word_size, num_words))
+        self.sram = sram(c, name="sram_{}ws_{}words".format(word_size, num_words))
+
+        self.sram_spice = OPTS.openram_temp + "temp.sp"
+        self.sram.sp_write(self.sram_spice)
+        
+    def get_sram_data(self, corner):
+        """Generates the delay object using the corner and runs a simulation for data."""
+        from characterizer import model_check
+        self.delay_obj = model_check(self.sram.s, self.sram_spice, corner)
+
+        import tech
+        #Only 1 at a time
+        probe_address = "1" * self.sram.s.addr_size
+        probe_data = self.sram.s.word_size - 1
+        loads = [tech.spice["msflop_in_cap"]*4]
+        slews = [tech.spice["rise_time"]*2]
+
+        sram_data = self.delay_obj.analyze(probe_address,probe_data,slews,loads)
+        
+        return sram_data
+       
+    def remove_lists_from_dict(self, dict):
+        """Check all the values in the dict and replaces the list items with its first value."""
+       #This is useful because the tests performed here only generate 1 value but a list
+       #with 1 item makes writing it to a csv later harder.
+        for key in dict.keys():
+            if type(dict[key]) is list:
+                if len(dict[key]) > 0:
+                    dict[key] = dict[key][0]
+                else:
+                    del dict[key]
+                    
+    def was_delay_chain_resized(self):
+        """Accesses the dc resize boolean in the control logic module."""
+        #FIXME:assumes read/write port only
+        return self.sram.s.control_logic_rw.delay_chain_resized
+                
+# instantiate a copdsay of the class to actually run the test
+if __name__ == "__main__":
+    (OPTS, args) = globals.parse_args()
+    del sys.argv[1:]
+    header(__file__, OPTS.tech_name)
+    unittest.main()
diff --git a/compiler/tests/testutils.py b/compiler/tests/testutils.py
index 6b2a7dcf..4340bce6 100755
--- a/compiler/tests/testutils.py
+++ b/compiler/tests/testutils.py
@@ -21,7 +21,8 @@ class openram_test(unittest.TestCase):
         if result != 0:
             self.fail("DRC failed: {}".format(w.name))
 
-        self.cleanup()
+        if OPTS.purge_temp:
+            self.cleanup()
     
     def local_check(self, a, final_verification=False):
 
@@ -62,6 +63,9 @@ class openram_test(unittest.TestCase):
         delay_obj.set_load_slew(load, slew)
         delay_obj.set_probe(probe_address="1"*sram.addr_size, probe_data=(sram.word_size-1))
         test_port = delay_obj.read_ports[0] #Only test one port, assumes other ports have similar period.
+        delay_obj.create_signal_names()
+        delay_obj.create_measurement_names()
+        delay_obj.create_measurement_objects()
         delay_obj.find_feasible_period_one_port(test_port) 
         return delay_obj.period        
             
diff --git a/technology/freepdk45/tech/tech.py b/technology/freepdk45/tech/tech.py
index 14ce1953..a0ba8cbc 100644
--- a/technology/freepdk45/tech/tech.py
+++ b/technology/freepdk45/tech/tech.py
@@ -271,7 +271,12 @@ spice["fet_models"] = { "TT" : [SPICE_MODEL_DIR+"/models_nom/PMOS_VTG.inc",SPICE
                         "FF" : [SPICE_MODEL_DIR+"/models_ff/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ff/NMOS_VTG.inc"],
                         "SF" : [SPICE_MODEL_DIR+"/models_ss/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ff/NMOS_VTG.inc"],
                         "FS" : [SPICE_MODEL_DIR+"/models_ff/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ss/NMOS_VTG.inc"],
-                        "SS" : [SPICE_MODEL_DIR+"/models_ss/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ss/NMOS_VTG.inc"]}
+                        "SS" : [SPICE_MODEL_DIR+"/models_ss/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ss/NMOS_VTG.inc"],
+                        "ST" : [SPICE_MODEL_DIR+"/models_ss/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_nom/NMOS_VTG.inc"],
+                        "TS" : [SPICE_MODEL_DIR+"/models_nom/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ss/NMOS_VTG.inc"],
+                        "FT" : [SPICE_MODEL_DIR+"/models_ff/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_nom/NMOS_VTG.inc"],
+                        "TF" : [SPICE_MODEL_DIR+"/models_nom/PMOS_VTG.inc",SPICE_MODEL_DIR+"/models_ff/NMOS_VTG.inc"],
+                        }
 
 #spice stimulus related variables
 spice["feasible_period"] = 5         # estimated feasible period in ns
@@ -328,12 +333,15 @@ spice["nand2_transition_prob"] = .1875    # Transition probability of 2-input na
 spice["nand3_transition_prob"] = .1094    # Transition probability of 3-input nand.
 spice["nor2_transition_prob"] = .1875     # Transition probability of 2-input nor.
 
-#Logical Effort relative values for the Handmade cells
+#Parameters related to sense amp enable timing and delay chain/RBL sizing
+parameter["static_delay_stages"] = 4
+parameter["static_fanout_per_stage"] = 3
 parameter["dff_clk_cin"] = 30.6             #relative capacitance
 parameter["6tcell_wl_cin"] = 3              #relative capacitance
-parameter["min_inv_para_delay"] = .5        #Tau delay units
+parameter["min_inv_para_delay"] = 2.4        #Tau delay units
 parameter["sa_en_pmos_size"] = .72          #micro-meters
 parameter["sa_en_nmos_size"] = .27          #micro-meters
+parameter["rbl_height_percentage"] = .5     #Height of RBL compared to bitcell array 
 
 ###################################################
 ##END Spice Simulation Parameters
diff --git a/technology/scn4m_subm/tech/tech.py b/technology/scn4m_subm/tech/tech.py
index 3b7e2142..1add9937 100755
--- a/technology/scn4m_subm/tech/tech.py
+++ b/technology/scn4m_subm/tech/tech.py
@@ -236,7 +236,12 @@ spice["fet_models"] = { "TT" : [SPICE_MODEL_DIR+"/nom/pmos.sp",SPICE_MODEL_DIR+"
                         "FF" : [SPICE_MODEL_DIR+"/ff/pmos.sp",SPICE_MODEL_DIR+"/ff/nmos.sp"],
                         "FS" : [SPICE_MODEL_DIR+"/ff/pmos.sp",SPICE_MODEL_DIR+"/ss/nmos.sp"],
                         "SF" : [SPICE_MODEL_DIR+"/ss/pmos.sp",SPICE_MODEL_DIR+"/ff/nmos.sp"],                        
-                        "SS" : [SPICE_MODEL_DIR+"/ss/pmos.sp",SPICE_MODEL_DIR+"/ss/nmos.sp"] }
+                        "SS" : [SPICE_MODEL_DIR+"/ss/pmos.sp",SPICE_MODEL_DIR+"/ss/nmos.sp"],
+                        "ST" : [SPICE_MODEL_DIR+"/ss/pmos.sp",SPICE_MODEL_DIR+"/nom/nmos.sp"],
+                        "TS" : [SPICE_MODEL_DIR+"/nom/pmos.sp",SPICE_MODEL_DIR+"/ss/nmos.sp"],
+                        "FT" : [SPICE_MODEL_DIR+"/ff/pmos.sp",SPICE_MODEL_DIR+"/nom/nmos.sp"],
+                        "TF" : [SPICE_MODEL_DIR+"/nom/pmos.sp",SPICE_MODEL_DIR+"/ff/nmos.sp"],
+                        }
                         
 
 #spice stimulus related variables
@@ -295,11 +300,14 @@ spice["nand3_transition_prob"] = .1094    # Transition probability of 3-input na
 spice["nor2_transition_prob"] = .1875     # Transition probability of 2-input nor.
 
 #Logical Effort relative values for the Handmade cells
+parameter["static_delay_stages"] = 4
+parameter["static_fanout_per_stage"] = 3
 parameter["dff_clk_cin"] = 27.5
 parameter["6tcell_wl_cin"] = 2
 parameter["min_inv_para_delay"] = .5
 parameter["sa_en_pmos_size"] = 24*_lambda_
 parameter["sa_en_nmos_size"] = 9*_lambda_
+parameter["rbl_height_percentage"] = .5     #Height of RBL compared to bitcell array 
 
 ###################################################
 ##END Spice Simulation Parameters