mirror of
https://github.com/myhdl/myhdl.git
synced 2024-12-14 07:44:38 +08:00
53 lines
1.2 KiB
Python
53 lines
1.2 KiB
Python
import operator
|
|
|
|
sec = 1e9
|
|
|
|
ODD, EVEN, MARK, SPACE = range(4)
|
|
|
|
class Error(Exception):
|
|
pass
|
|
|
|
class ParityError(Error):
|
|
pass
|
|
|
|
class StopBitError(Error):
|
|
pass
|
|
|
|
class Config(object):
|
|
|
|
""" rs232 configuration object.
|
|
|
|
Attributes:
|
|
baud_rate -- baud_rate in bits per second
|
|
n_bits -- number of data bits: 7 or 8
|
|
n_stops -- number of stop bits: 1 or 2
|
|
parity -- parity configuration: None, ODD, EVEN, MARK or SPACE
|
|
|
|
"""
|
|
|
|
__slots__ = ("baud_rate", "n_bits", "n_stops", "parity")
|
|
|
|
def __init__(self, baud_rate=9600, n_bits=8, n_stops=1, parity=None):
|
|
""" Return new Config object with actual or default parameters """
|
|
self.baud_rate = baud_rate
|
|
self.n_bits = n_bits
|
|
self.n_stops = n_stops
|
|
self.parity = parity
|
|
|
|
|
|
def parity(data, cfg):
|
|
""" Return data parity as configured """
|
|
if cfg == ODD:
|
|
return not reduceXor(data[8:])
|
|
elif cfg== EVEN:
|
|
return reduceXor(data[8:])
|
|
elif cfg == MARK:
|
|
return 1
|
|
elif cfg == SPACE:
|
|
return 0
|
|
|
|
def reduceXor(bv):
|
|
""" Return reduction xor of all bits in bv """
|
|
return reduce(operator.xor, [b for b in bv])
|
|
|