OpenFPGA/openfpga_flow/scripts/lib/parse_pcf.py

45 lines
1.2 KiB
Python
Executable File

"""
Supported PCF commands:
* set_io <net> <pad> - constrain a given <net> to a given physical <pad> in eFPGA pinout.
* set_clk <pin> <net> - constrain a given global clock <pin> to a given <net>
Every tile where <net> is present will be constrained to use a given global clock.
"""
from collections import namedtuple
import re
PcfIoConstraint = namedtuple('PcfIoConstraint', 'net pad line_str line_num')
PcfClkConstraint = namedtuple('PcfClkConstraint', 'pin net')
def parse_simple_pcf(f):
""" Parse a simple PCF file object and yield PcfIoConstraint objects. """
for line_number, line in enumerate(f):
line_number += 1
# Remove comments.
args = re.sub(r"#.*", "", line.strip()).split()
if not args:
continue
# Ignore arguments.
args = [arg for arg in args if arg[0] != '-']
assert len(args) == 3, args
if args[0] == 'set_io':
yield PcfIoConstraint(
net=args[1],
pad=args[2],
line_str=line.strip(),
line_num=line_number,
)
if args[0] == 'set_clk':
yield PcfClkConstraint(
pin=args[1],
net=args[2],
)