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Functional simulation uses threshold for high and low noise margins

This commit is contained in:
Matt Guthaus 2018-11-28 16:55:04 -08:00
parent 25ae3a5eae
commit 3cfe74cefb
2 changed files with 8 additions and 4 deletions
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9
compiler/characterizer/functional.py
View File

@ -29,6 +29,7 @@ class functional(simulation):
self.set_spice_constants()
self.set_stimulus_variables()
self.create_signal_names()
# Number of checks can be changed
self.num_cycles = 2
@ -141,17 +142,17 @@ class functional(simulation):
sp_read_value = ""
for bit in range(self.word_size):
value = parse_spice_list("timing", "v{0}.{1}ck{2}".format(dout_port.lower(),bit,check))
if value > 0.88 * self.vdd_voltage:
if value > self.v_high:
sp_read_value = "1" + sp_read_value
elif value < 0.12 * self.vdd_voltage:
elif value < self.v_low:
sp_read_value = "0" + sp_read_value
else:
error ="FAILED: {0}_{1} value {2} at time {3}n does not fall within noise margins <{4} or >{5}.".format(dout_port,
bit,
value,
eo_period,
0.12*self.vdd_voltage,
0.88*self.vdd_voltage)
self.v_low,
self.v_high)
return (0, error)
self.read_check.append([sp_read_value, dout_port, eo_period, check])

3
compiler/characterizer/simulation.py
View File

@ -37,6 +37,9 @@ class simulation():
self.period = tech.spice["feasible_period"]
self.slew = tech.spice["rise_time"]*2
self.load = tech.spice["msflop_in_cap"]*4
self.v_high = self.vdd_voltage - tech.spice["v_threshold_typical"]
self.v_low = tech.spice["v_threshold_typical"]
self.gnd_voltage = 0
def set_stimulus_variables(self):