def voltage_deductions(in_pins, out_pins, logic_function, active_pin,
netlist_pins):
""" Setup the Supply voltage and Logic Signal as per the logic function """
in_pins = in_pins.replace(active_pin, '') + ' ' + active_pin
pos_unate, pins_voltages = truths.Truths(in_pins.split(),
[logic_function]).truth_table()
# Setting up Power Supplies Voltages
power_supplies = ['VPWR', 'VDD', 'VPB']
gnd_supplies = ['VGND', 'VNB', 'VSS']
power_str = '\n'.join([
f'V{net} {net} 0 DC {VDD}' for net in power_supplies
if net in netlist_pins
])
gnd_str = '\n'.join([
f'V{net} {net} 0 DC 0' for net in gnd_supplies if net in netlist_pins
])
# Setting Up Signal Voltages
active_pin_voltage = f'V{active_pin} {active_pin} 0 PULSE(0 {VDD} 0 0.01n 0.01n 50ns 100ns)'
other_pins_voltage = []
for net, logic in pins_voltages.items():
if logic == 0:
other_pins_voltage.append(f'V{net} {net} 0 DC 0')
elif logic == 1:
other_pins_voltage.append(f'V{net} {net} 0 DC {VDD}')
other_pins_vol_str = '\n'.join(other_pins_voltage)
power_supplies = power_str + '\n' + gnd_str
signal_supplies = active_pin_voltage + '\n' + other_pins_vol_str
return power_supplies, signal_supplies, pos_unate
def ngpost_timing(act_out_pin, func, signal_source, active_pin):
""" Generate ngspice control commands for timing_harness"""
in_pins = ' '.join(input_pins).replace(active_pin, '') + ' ' + active_pin
working_func = convert_logical(func)
pos_unate, pins_voltages = truths.Truths(in_pins.split(),
[working_func]).truth_table()
extra_alter_source = []
missing_voltage_source = []
for in_pin in pins_voltages.keys():
if pins_voltages[in_pin] == 1: voltage = power_volts
else: voltage = 0
if in_pin in signal_sources.keys():
extra_alter_source.append(
f'alter @{signal_sources[in_pin]}[PWL] = [ 0 {voltage} ]')
else:
missing_voltage_source.append(f'V{in_pin} {in_pin} 0 DC 0')
extra_alter_source_str = '\n'.join(extra_alter_source)
# TODO: Shift this text based template to Jinja Templates if necessary
control_str = \
f"""let run = 0 \n
shell rm {working_folder}/input_transition.txt
shell rm {working_folder}/cell_fall.txt
shell rm {working_folder}/cell_rise.txt
shell rm {working_folder}/fall_transition.txt
shell rm {working_folder}/rise_transition.txt
foreach in_delay {input_transition_time}
* Initiating Text Files in folder data
echo "input_transition:$in_delay" >> {working_folder}/input_transition.txt
echo "input_transition:$in_delay" >> {working_folder}/cell_fall.txt
echo "input_transition:$in_delay" >> {working_folder}/cell_rise.txt
echo "input_transition:$in_delay" >> {working_folder}/fall_transition.txt
echo "input_transition:$in_delay" >> {working_folder}/rise_transition.txt
* 1.666 to match the slew rate
let actual_rtime = $in_delay*1.666
* Input Vector - Load Cap values(index2)
foreach out_cap {output_caps}
reset
* Changing the V2 Supply Rise time as per the Input Rise Time vector
alter @{signal_source}[pulse] = [ 0 {power_volts} 0 $&actual_rtime $&actual_rtime 50ns 100ns ]
{extra_alter_source_str}
* Changing the C1 value as per the foreach list
alter CLOAD $out_cap
tran 0.01n 300ns
run
reset
* Verification of INPUT RISE TIME
meas tran ts1 when v({active_pin})={float(power_volts)*0.8} RISE=1
meas tran ts2 when v({active_pin})={float(power_volts)*0.2} RISE=1
meas tran ts3 when v({active_pin})={float(power_volts)*0.8} FALL=1
meas tran ts4 when v({active_pin})={float(power_volts)*0.2} FALL=1
let RISE_IN_SLEW = (ts1-ts2)/{time_unit}
let FALL_IN_SLEW = (ts4-ts3)/{time_unit}
echo "actual_rise_slew:$&RISE_IN_SLEW" >> {working_folder}/input_transition.txt
echo "actual_fall_slew:$&FALL_IN_SLEW" >> {working_folder}/input_transition.txt
print run
* Measuring Cell Fall Time @ 50% of VDD({float(power_volts)}V)
meas tran tinfall when v({active_pin})={float(power_volts)*0.5} FALL=1
meas tran tofall when v({act_out_pin})={float(power_volts)*0.5} FALL=1
let cfall = (tofall-tinfall)/{time_unit}
if abs(cfall)>20
meas tran tinfall when v({active_pin})={float(power_volts)*0.5} Rise=1
meas tran tofall when v({act_out_pin})={float(power_volts)*0.5} FALL=1
let cfall = abs(tofall-tinfall)/{time_unit}
end
print cfall
echo "out_cap:$out_cap:cell_fall:$&cfall" >> {working_folder}/cell_fall.txt
* Measuring Cell Rise Time @ 50% of VDD({float(power_volts)}V)
meas tran tinrise when v({active_pin})={float(power_volts)*0.5} RISE=1
meas tran torise when v({act_out_pin})={float(power_volts)*0.5} RISE=1
let crise = (torise-tinrise)/{time_unit}
if abs(crise)>20
meas tran tinrise when v({active_pin})={float(power_volts)*0.5} FALL=1
meas tran torise when v({act_out_pin})={float(power_volts)*0.5} RISE=1
let crise = abs(tinrise-torise)/{time_unit}
end
print crise
echo "out_cap:$out_cap:cell_rise:$&crise" >> {working_folder}/cell_rise.txt
* Measuring Fall transition Time @ 80-20% of VDD({float(power_volts)}V)
meas tran ft1 when v({act_out_pin})={float(power_volts)*0.8} FALL=2
meas tran ft2 when v({act_out_pin})={float(power_volts)*0.2} FALL=2
let fall_tran = (ft2-ft1)/{time_unit}
print fall_tran
echo "out_cap:$out_cap:fall_transition:$&fall_tran" >> {working_folder}/fall_transition.txt
* Measuring Rise transition Time @ 20-80% of VDD({float(power_volts)}V)
meas tran rt1 when v({act_out_pin})={float(power_volts)*0.8} RISE=2
meas tran rt2 when v({act_out_pin})={float(power_volts)*0.2} RISE=2
let rise_tran = ((rt1-rt2)/{time_unit})
print rise_tran
echo "out_cap:$out_cap:rise_transition:$&rise_tran" >> {working_folder}/rise_transition.txt
let run = run + 1
* plot a y
end
end"""
return control_str