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Added better port selection to bitline measurements.

This commit is contained in:
Hunter Nichols 2018-12-12 15:59:20 -08:00
parent 0a26e40022
commit 50f13eabce
1 changed files with 29 additions and 9 deletions
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38
compiler/characterizer/bitline_delay.py
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@ -45,9 +45,19 @@ class bitline_delay(delay):
Write the measure statements to quantify the delay and power results for a read port.
"""
# add measure statements for delays/slews
measure_bit = 0
self.stim.gen_meas_find_voltage("bl_volt", "Xsram.s_en0", "Xsram.Xbank0.bl_{}".format(measure_bit), .5, "RISE", 3*self.period)
self.stim.gen_meas_find_voltage("br_volt", "Xsram.s_en0", "Xsram.Xbank0.br_{}".format(measure_bit), .5, "RISE", 3*self.period)
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"]])
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)
@ -74,10 +84,20 @@ class bitline_delay(delay):
# This also ensures we will have a H->L transition on the next read
self.add_read("R data 1 address {} to set DOUT caps".format(inverse_address),
inverse_address,data_zeros,read_port)
self.measure_cycles[read_port]["read1"] = len(self.cycle_times)-1
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:
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 run_delay_simulation(self):
"""
This tries to simulate a period and checks if the result works. If
@ -114,15 +134,15 @@ class bitline_delay(delay):
self.load=max(loads)
self.slew=max(slews)
port = 0
read_port = self.read_ports[0] #only test the first read port
bitline_swings = {}
self.targ_read_ports = [self.read_ports[port]]
self.targ_write_ports = [self.write_ports[port]]
self.targ_read_ports = [read_port]
self.targ_write_ports = [self.write_ports[0]]
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[port][mname]
bitline_swings[mname] = results[read_port][mname]
debug.info(1,"Bitline values (bl/br): {}".format(bitline_swings))
return bitline_swings