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用python实现网表分模块统计面积

时间:2022-07-04 16:16:15 来源:

虽然dc也有report_area -hier命令来报告各级模块的面积,本python方案看似有点造轮子,但还是有一定的便利性。一、不受网表类型的限制,综合网表、DFT网表、APR都可以。二、可以过滤面积小于指定值的小模块,比如工具自动插入的ICG模块。三、还可以根据面积占比做排序,方便分析面积的瓶颈。

一、读入网表

下面先读入网表,并分模块识别每个模块内部的stdcell和子模块。这部分与《用python实现分模块按cell类型统计cell个数并降序排列》的方法相同,所以这里直接导入netlistparser.py。

import netlistparser as nlparser

import sys

vlog_netlist_file = sys.argv[2]

modules = nlparser.read_vlog_netlist(vlog_netlist_file)

这样网表就读到了内部python字典里,结构如下:

"moduleA": {

"module_name": "moduleA",

"insts": {

"u_AND2_01": "AND2X1",

"u_AND2_02": "AND2X1",

"u_OR2_01": "OR2X1",

"u_INV_01": "INVX1"

},

"moduleB": {

"module_name": "moduleB",

"insts": {

"u_AND2_01": "AND2X1",

"u_AND2_02": "AND2X1",

"u_OR2_01": "OR2X1",

"u_INV_01": "INVX1"

},

二、读入lib库

stdcell的面积信息存储在fab提供的lib文件里,所以我们需要从lib里读到每种cell的面积,方法如下:

# libparser.py

import sys

import re

import json

def read_library(file_name):

cells = {}

lib_lines = open(file_name, 'r').readlines()

cell_start = 0

pin_start = 0

total_lines = len(lib_lines)

print('')

for i in range(total_lines):

line = lib_lines[i]

print(' {}%'.format(round(100 * i / total_lines)))

cell_s_m = re.search(r'cells*((w+))s+{', line)

area_m = re.search(r'sareas+:s+(S+)s*;', line)

pin_s_m = re.search(r'spin((w+))s+{', line)

dir_m = re.search(r'sdirections+:s+(w+)', line)

func_m = re.search(r'sfunctions+:s+"(.*)"', line)

end_m = re.search(r'}', line)

if cell_s_m:

cell_start = 1

cell = {}

cell_name = cell_s_m.group(1)

cell['cell_name'] = cell_name

pins = []

cell['pins'] = pins

cells[cell_name] = cell

if cell_start and area_m:

area = area_m.group(1)

cell['area'] = round(float(area), 4)

if cell_start and pin_s_m:

pin_start = 1

pin = {}

pin_name = pin_s_m.group(1)

pin['pin_name'] = pin_name

if cell_start and dir_m:

pin_dir = dir_m.group(1)

pin['pin_dir'] = pin_dir

if cell_start and func_m:

pin_func = func_m.group(1)

pin['pin_func'] = pin_func

if cell_start and pin_start and end_m:

pin_start = 0

pins.append(pin)

return cells

def get_cell_area(cells, cell_name):

if cell_name in cells:

return cells[cell_name]['area']

else:

return 0

def is_libcell(cells, cell_name):

if cell_name in cells:

return True

else:

return False

def write_lib_info(lib_info, file_name):

f = open(file_name, 'w')

f.write(json.dumps(lib_info, indent=4))

f.close()

其中,read_library()函数实现了用正则读取lib文件里的cell名字、area、pin、pin方向、function等信息。今天只需要用到cell名字和面积。其它信息是为了后续扩展其它功能做准备。

get_cell_area()提供了读取指定cell面积的接口。is_libcell()实现了判断是libcell还是一般的设计上的子模块。

write_lib_info()可以将lib库的字典写到json文件里,方便调试。

接下来,用这个libparser读入lib库:

import libparser

import sys

lib_file = sys.argv[1]

lib_info = libparser.read_library(lib_file)

三、面积递归统计

我们从top design开始,当遇到stdcell中的cell则累加,当遇到子模块则递归。直到子模块不再含有其它子模块(仅由stdcell组成)时,则返回。

area_info = {}

def report_area(modules, lib_info, module_name):

global area_info

area = 0

insts = modules[module_name]['insts']

for inst in insts:

cell_inst = inst

cell_type = insts[inst]

if cell_type in area_info:

area = area + area_info[cell_type]

elif libparser.is_libcell(lib_info, cell_type):

area = area + libparser.get_cell_area(lib_info, cell_type)

else:

# 递归

report_area(modules, lib_info, cell_type)

area = area + area_info[cell_type]

area_info[module_name] = area

四、打印面积

打印的同时,可以做一些过滤或者排序。

for module in area_info:

if not re.search(r'CLOCK_GATE', module):

print(module, round(area_info[module], 4))

效果如下:

原文标题:用python实现网表分模块统计面积


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