cat.py: it's counter freq, not cpu freq

import sys

import time

cpu_freq = None

counter_freq = None

timer_overflow = None

def handle_line(line):

    if cpu_freq is not None:

    if counter_freq is not None:

        print_line = line

        for match in re.finditer("(\d+)/(\d+) cycles", line):

            cycles = int(match.group(1))

            overflows = int(match.group(2))

            ms = (cycles + timer_overflow * overflows) * 1000 / cpu_freq

            ms = (cycles + timer_overflow * overflows) * 1000 / counter_freq

            match_line = f"{cycles}/{overflows} cycles"

            new_line = f"{ms} ms ({cycles}/{overflows} cycles)"

            print_line = re.sub(match_line, new_line, print_line)

    baud = int(sys.argv[2])

    if len(sys.argv) > 4:

        cpu_freq = int(sys.argv[3])

        counter_freq = int(sys.argv[3])

        timer_overflow = int(sys.argv[4])

    monitor = SerialMonitor(tty, baud, handle_line)

    time.sleep(5)

    time.sleep(20)

    monitor.close()