用python實(shí)現(xiàn)網(wǎng)表分模塊統(tǒng)計(jì)面積

雖然dc也有report_area -hier命令來(lái)報(bào)告各級(jí)模塊的面積，本python方案看似有點(diǎn)造輪子，但還是有一定的便利性。一、不受網(wǎng)表類型的限制，綜合網(wǎng)表、DFT網(wǎng)表、APR都可以。二、可以過(guò)濾面積小于指定值的小模塊，比如工具自動(dòng)插入的ICG模塊。三、還可以根據(jù)面積占比做排序，方便分析面積的瓶頸。

一、讀入網(wǎng)表

下面先讀入網(wǎng)表，并分模塊識(shí)別每個(gè)模塊內(nèi)部的stdcell和子模塊。這部分與《用python實(shí)現(xiàn)分模塊按cell類型統(tǒng)計(jì)cell個(gè)數(shù)并降序排列》的方法相同，所以這里直接導(dǎo)入netlistparser.py。

import netlistparser as nlparser
import sys


vlog_netlist_file = sys.argv[2]
modules=nlparser.read_vlog_netlist(vlog_netlist_file)

這樣網(wǎng)表就讀到了內(nèi)部python字典里，結(jié)構(gòu)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、讀入lib庫(kù)

stdcell的面積信息存儲(chǔ)在fab提供的lib文件里，所以我們需要從lib里讀到每種cell的面積，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('33[1F {}%'.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()函數(shù)實(shí)現(xiàn)了用正則讀取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名字和面積。其它信息是為了后續(xù)擴(kuò)展其它功能做準(zhǔn)備。

get_cell_area()提供了讀取指定cell面積的接口。is_libcell()實(shí)現(xiàn)了判斷是libcell還是一般的設(shè)計(jì)上的子模塊。

write_lib_info()可以將lib庫(kù)的字典寫到j(luò)son文件里，方便調(diào)試。

接下來(lái)，用這個(gè)libparser讀入lib庫(kù)：

import libparser
import sys


lib_file = sys.argv[1]
lib_info=libparser.read_library(lib_file)

三、面積遞歸統(tǒng)計(jì)

我們從top design開(kāi)始，當(dāng)遇到stdcell中的cell則累加，當(dāng)遇到子模塊則遞歸。直到子模塊不再含有其它子模塊（僅由stdcell組成）時(shí)，則返回。

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:
#遞歸
report_area(modules,lib_info,cell_type)
            area = area + area_info[cell_type]
    
area_info[module_name]=area

四、打印面積

打印的同時(shí)，可以做一些過(guò)濾或者排序。

for module in area_info:
        if not re.search(r'CLOCK_GATE', module):
            print(module, round(area_info[module], 4))

效果如下：