Added more variance analysis for the delay data

compiler/characterizer/model_check.py

@@ -38,6 +38,7 @@ class model_check(delay):
         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())]
@@ -61,14 +62,14 @@ class model_check(delay):
                                ["Xsram.wl_en0", "Xsram.Xbank0.Xwordline_driver0.wl_bar_{}".format(self.wordline_row)]+\
                                wl_driver_signals+\
                                ["Xsram.Xbank0.wl_{}".format(self.wordline_row)]
-        self.rbl_en_signal_names = ["Xsram.Xcontrol0.gated_clk_bar", "Xsram.Xcontrol0.Xand2_rbl_in.zb_int", "Xsram.Xcontrol0.rbl_in"]+\
+        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()

compiler/tests/config_data.py

@@ -4,7 +4,7 @@ num_words = 16
 
 tech_name = "freepdk45"
 #process_corners = ["TT", "FF", "SS", "SF", "FS"]
-process_corners = ["TT"]
+process_corners = ["TT", "FF", "SS"]
 supply_voltages = [1.0]
 temperatures = [25]
 

compiler/tests/delay_data_collection.py

@@ -20,28 +20,60 @@ MODEL_DIR = "model_data/"
 class data_collection(openram_test):
 
     def runTest(self):
-        ratio_data = self.calculate_delay_ratios_of_srams()
-        self.display_data(ratio_data)
-        # word_size, num_words, words_per_row = 4, 16, 1 
-        # self.init_data_gen()
-        # self.set_delay_chain(2,3)
-        # self.save_data_sram_corners(word_size, num_words, words_per_row)
-        # wl_dataframe, sae_dataframe = self.get_csv_data()
-        # self.evaluate_data(wl_dataframe, sae_dataframe)
-        
-        #Run again but with different delay chain sizes
-        # self.init_data_gen() 
-        # self.set_delay_chain(4,2)
-        # self.save_data_sram_corners(word_size, num_words, words_per_row)
-        # wl_dataframe, sae_dataframe = self.get_csv_data()
-        # self.evaluate_data(wl_dataframe, sae_dataframe)
-        
-        # model_delay_ratios, meas_delay_ratios, ratio_error = self.compare_model_to_measure()
-        # debug.info(1, "model_delay_ratios={}".format(model_delay_ratios))
-        # debug.info(1, "meas_delay_ratios={}".format(meas_delay_ratios))
-        # debug.info(1, "ratio_error={}".format(ratio_error))
-        # globals.end_openram()
     
+        #Uncomment this for model evaluation
+        # ratio_data = self.calculate_delay_ratios_of_srams()
+        # self.display_data(ratio_data)
+
+        self.run_delay_chain_variation_analysis()
+        
+        globals.end_openram()
+    
+    def run_delay_chain_variation_analysis(self):
+        """Generates sram with different delay chain configs over different corners and 
+           analyzes delay 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)]
+        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()
+            var = self.calculate_delay_chain_variance(sae_dataframe)
+            dc_vars.append(var)
+            debug.info(1,"DC config={}, variance={}".format((stages,fanout), var))
+        
+        self.plot_data(dc_config_list, dc_vars)
+        #display data
+    
+    def calculate_delay_chain_variance(self, sae_dataframe):
+        """Determines the delay variance of the delay chain over 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))
+        
+        #calculate mean then variance 
+        m = sum(delay_sums) / len(delay_sums)
+        delay_variance = sum((xi - m) ** 2 for xi in delay_sums) / len(delay_sums)
+        return delay_variance
+    
+    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 calculate_delay_ratios_of_srams(self):
         """Runs delay measurements on several sram configurations.
         Computes the delay ratio for each one."""