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High-to-low delays and slews are copied from the low-to-high values to simplify lib file results. FIXME

This commit is contained in:
Hunter Nichols 2018-11-19 15:40:26 -08:00
parent d3c47ac976
commit a55d907d03
2 changed files with 18 additions and 7 deletions
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10
compiler/characterizer/delay.py
View File

@ -669,8 +669,18 @@ class delay(simulation):
self.period = min_period self.period = min_period
char_port_data = self.simulate_loads_and_slews(slews, loads, leakage_offset) char_port_data = self.simulate_loads_and_slews(slews, loads, leakage_offset)
#FIXME: low-to-high delays are altered to be independent of the period. This makes the lib results less accurate.
self.alter_lh_char_data(char_port_data)
return (char_sram_data, char_port_data) return (char_sram_data, char_port_data)
def alter_lh_char_data(self, char_port_data):
"""Copies high-to-low data to low-to-high data to make them consistent on the same clock edge."""
#This is basically a hack solution which should be removed/fixed later.
for port in self.all_ports:
char_port_data[port]['delay_lh'] = char_port_data[port]['delay_hl']
char_port_data[port]['slew_lh'] = char_port_data[port]['slew_hl']
def simulate_loads_and_slews(self, slews, loads, leakage_offset): def simulate_loads_and_slews(self, slews, loads, leakage_offset):
"""Simulate all specified output loads and input slews pairs of all ports""" """Simulate all specified output loads and input slews pairs of all ports"""
measure_data = self.get_empty_measure_data_dict() measure_data = self.get_empty_measure_data_dict()

15
compiler/modules/control_logic.py
View File

@ -33,7 +33,7 @@ class control_logic(design.design):
self.sram=sram self.sram=sram
#self.sram=None #disable re-sizing for debugging #self.sram=None #disable re-sizing for debugging
self.wl_timing_tolerance = 1 #Determines how much larger the sen delay should be. Accounts for possible error in model. self.wl_timing_tolerance = 1 #Determines how much larger the sen delay should be. Accounts for possible error in model.
self.parasitic_inv_delay = 0 #Keeping 0 for now until further testing. self.parasitic_inv_delay = parameter["min_inv_para_delay"] #Keeping 0 for now until further testing.
if self.port_type == "rw": if self.port_type == "rw":
self.num_control_signals = 2 self.num_control_signals = 2
@ -106,14 +106,15 @@ class control_logic(design.design):
self.replica_bitline = replica_bitline([delay_fanout_heuristic]*delay_stages_heuristic, bitcell_loads, name="replica_bitline_"+self.port_type) self.replica_bitline = replica_bitline([delay_fanout_heuristic]*delay_stages_heuristic, bitcell_loads, name="replica_bitline_"+self.port_type)
self.set_sen_wl_delays() self.set_sen_wl_delays()
if self.sram != None and not self.does_sen_total_timing_match(): if self.sram != None and not self.does_sen_rise_fall_timing_match():
#This resizes to match fall and rise delays, can make the delay chain weird sizes. #This resizes to match fall and rise delays, can make the delay chain weird sizes.
#stage_list = self.get_dynamic_delay_fanout_list(delay_stages_heuristic, delay_fanout_heuristic) stage_list = self.get_dynamic_delay_fanout_list(delay_stages_heuristic, delay_fanout_heuristic)
#self.replica_bitline = replica_bitline(stage_list, bitcell_loads, name="replica_bitline_resized_"+self.port_type) self.replica_bitline = replica_bitline(stage_list, bitcell_loads, name="replica_bitline_resized_"+self.port_type)
#This resizes based on total delay. #This resizes based on total delay.
delay_stages, delay_fanout = self.get_dynamic_delay_chain_size(delay_stages_heuristic, delay_fanout_heuristic) # delay_stages, delay_fanout = self.get_dynamic_delay_chain_size(delay_stages_heuristic, delay_fanout_heuristic)
self.replica_bitline = replica_bitline([delay_fanout]*delay_stages, bitcell_loads, name="replica_bitline_resized_"+self.port_type) # self.replica_bitline = replica_bitline([delay_fanout]*delay_stages, bitcell_loads, name="replica_bitline_resized_"+self.port_type)
self.sen_delay_rise,self.sen_delay_fall = self.get_delays_to_sen() #get the new timing self.sen_delay_rise,self.sen_delay_fall = self.get_delays_to_sen() #get the new timing
self.add_mod(self.replica_bitline) self.add_mod(self.replica_bitline)
@ -214,7 +215,7 @@ class control_logic(design.design):
def calculate_stages_with_fixed_fanout(self, required_delay, fanout): def calculate_stages_with_fixed_fanout(self, required_delay, fanout):
from math import ceil from math import ceil
#Delay being negative is not an error. It implies that any amount of stages would have a negative effect on the overall delay #Delay being negative is not an error. It implies that any amount of stages would have a negative effect on the overall delay
if required_delay<=3: #3 is the minimum delay per stage. if required_delay <= 3+self.parasitic_inv_delay: #3 is the minimum delay per stage (with pinv=0).
return 1 return 1
delay_stages = ceil(required_delay/(fanout+1+self.parasitic_inv_delay)) delay_stages = ceil(required_delay/(fanout+1+self.parasitic_inv_delay))
return delay_stages return delay_stages