return (ones % 2) == 1
elif parity_type == 'even':
return (ones % 2) == 0
- else:
- raise Exception('Invalid parity type: %d' % parity_type)
+
+class SamplerateError(Exception):
+ pass
+
+class ChannelError(Exception):
+ pass
class Decoder(srd.Decoder):
api_version = 2
'values': ('lsb-first', 'msb-first')},
{'id': 'format', 'desc': 'Data format', 'default': 'ascii',
'values': ('ascii', 'dec', 'hex', 'oct', 'bin')},
- # TODO: Options to invert the signal(s).
+ {'id': 'invert_rx', 'desc': 'Invert RX?', 'default': 'no',
+ 'values': ('yes', 'no')},
+ {'id': 'invert_tx', 'desc': 'Invert TX?', 'default': 'no',
+ 'values': ('yes', 'no')},
)
annotations = (
('rx-data', 'RX data'),
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
- self.samplerate = value;
+ self.samplerate = value
# The width of one UART bit in number of samples.
self.bit_width = float(self.samplerate) / float(self.options['baudrate'])
self.databyte[rxtx] >>= 1
self.databyte[rxtx] |= \
(signal << (self.options['num_data_bits'] - 1))
- elif self.options['bit_order'] == 'msb-first':
+ else:
self.databyte[rxtx] <<= 1
self.databyte[rxtx] |= (signal << 0)
- else:
- raise Exception('Invalid bit order value: %s',
- self.options['bit_order'])
self.putg([rxtx + 12, ['%d' % signal]])
self.putx(rxtx, [rxtx, [oct(b)[2:].zfill(3)]])
elif f == 'bin':
self.putx(rxtx, [rxtx, [bin(b)[2:].zfill(8)]])
- else:
- raise Exception('Invalid data format option: %s' % f)
self.putbin(rxtx, (rxtx, bytes([b])))
self.putbin(rxtx, (2, bytes([b])))
self.putg([rxtx + 4, ['Stop bit', 'Stop', 'T']])
def decode(self, ss, es, data):
- if self.samplerate is None:
- raise Exception("Cannot decode without samplerate.")
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
for (self.samplenum, pins) in data:
# Note: Ignoring identical samples here for performance reasons
# continue
self.oldpins, (rx, tx) = pins, pins
+ if self.options['invert_rx'] == 'yes':
+ rx = not rx
+ if self.options['invert_tx'] == 'yes':
+ tx = not tx
+
# Either RX or TX (but not both) can be omitted.
has_pin = [rx in (0, 1), tx in (0, 1)]
if has_pin == [False, False]:
- raise Exception('Either TX or RX (or both) pins required.')
+ raise ChannelError('Either TX or RX (or both) pins required.')
# State machine.
for rxtx in (RX, TX):
self.get_parity_bit(rxtx, signal)
elif self.state[rxtx] == 'GET STOP BITS':
self.get_stop_bits(rxtx, signal)
- else:
- raise Exception('Invalid state: %s' % self.state[rxtx])
# Save current RX/TX values for the next round.
self.oldbit[rxtx] = signal
-