OpenRAM/compiler/characterizer/logical_effort.py

49 lines
2.0 KiB
Python

import debug
from tech import drc, parameter, spice
class logical_effort():
"""
Class to support the values behind logical effort. Useful for storing the different components
such as logical effort, electrical effort, and parasitic delay.
"""
beta = parameter["beta"]
min_inv_cin = 1+beta
pinv=parameter["min_inv_para_delay"]
def __init__(self, size, cin, cout, parasitic, out_is_rise=True):
self.cin = cin
self.cout = cout
self.logical_effort = (self.cin/size)/logical_effort.min_inv_cin
self.eletrical_effort = self.cout/self.cin
self.parasitic_scale = parasitic
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)
def get_stage_effort(self):
return self.logical_effort*self.eletrical_effort
def get_parasitic_delay(self, pinv):
return pinv * self.parasitic_scale
def get_stage_delay(self, pinv):
return self.get_stage_effort()+self.get_parasitic_delay(pinv)
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."""
total_rise_delay, total_fall_delay = calculate_relative_rise_fall_delays(stage_effort_list, pinv)
return total_rise_delay + total_fall_delay
def calculate_relative_rise_fall_delays(stage_effort_list, pinv=parameter["min_inv_para_delay"]):
"""Calculates the rise/fall delays of a given delay path made of a list of logical effort objects."""
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)
if stage.is_rise:
total_rise_delay += stage.get_stage_delay(pinv)
else:
total_fall_delay += stage.get_stage_delay(pinv)
return total_rise_delay, total_fall_delay