diff options
Diffstat (limited to 'decoders/uart/pd.py')
| -rw-r--r-- | decoders/uart/pd.py | 62 |
1 files changed, 57 insertions, 5 deletions
diff --git a/decoders/uart/pd.py b/decoders/uart/pd.py index 6c3d85c..ffacad9 100644 --- a/decoders/uart/pd.py +++ b/decoders/uart/pd.py @@ -124,14 +124,18 @@ class Decoder(srd.Decoder): ('tx-warnings', 'TX warnings'), ('rx-data-bits', 'RX data bits'), ('tx-data-bits', 'TX data bits'), + ('rx-break', 'RX break'), + ('tx-break', 'TX break'), ) annotation_rows = ( ('rx-data', 'RX', (0, 2, 4, 6, 8)), ('rx-data-bits', 'RX bits', (12,)), ('rx-warnings', 'RX warnings', (10,)), + ('rx-break', 'RX break', (14,)), ('tx-data', 'TX', (1, 3, 5, 7, 9)), ('tx-data-bits', 'TX bits', (13,)), ('tx-warnings', 'TX warnings', (11,)), + ('tx-break', 'TX break', (15,)), ) binary = ( ('rx', 'RX dump'), @@ -156,6 +160,12 @@ class Decoder(srd.Decoder): s, halfbit = self.samplenum, self.bit_width / 2.0 self.put(s - floor(halfbit), s + ceil(halfbit), self.out_python, data) + def putgse(self, ss, es, data): + self.put(ss, es, self.out_ann, data) + + def putpse(self, ss, es, data): + self.put(ss, es, self.out_python, data) + def putbin(self, rxtx, data): s, halfbit = self.startsample[rxtx], self.bit_width / 2.0 self.put(s - floor(halfbit), self.samplenum + ceil(halfbit), self.out_binary, data) @@ -175,6 +185,7 @@ class Decoder(srd.Decoder): self.startsample = [-1, -1] self.state = ['WAIT FOR START BIT', 'WAIT FOR START BIT'] self.databits = [[], []] + self.break_start = [None, None] def start(self): self.out_python = self.register(srd.OUTPUT_PYTHON) @@ -337,6 +348,13 @@ class Decoder(srd.Decoder): self.state[rxtx] = 'WAIT FOR START BIT' + def handle_break(self, rxtx): + self.putpse(self.frame_start[rxtx], self.samplenum, + ['BREAK', rxtx, 0]) + self.putgse(self.frame_start[rxtx], self.samplenum, + [rxtx + 14, ['Break condition', 'Break', 'Brk', 'B']]) + self.state[rxtx] = 'WAIT FOR START BIT' + def get_wait_cond(self, rxtx, inv): # Return condititions that are suitable for Decoder.wait(). Those # conditions either match the falling edge of the START bit, or @@ -373,6 +391,22 @@ class Decoder(srd.Decoder): elif state == 'GET STOP BITS': self.get_stop_bits(rxtx, signal) + def inspect_edge(self, rxtx, signal, inv): + # Inspect edges, independently from traffic, to detect break conditions. + if inv: + signal = not signal + if not signal: + # Signal went low. Start another interval. + self.break_start[rxtx] = self.samplenum + return + # Signal went high. Was there an extended period with low signal? + if self.break_start[rxtx] is None: + return + diff = self.samplenum - self.break_start[rxtx] + if diff >= self.break_min_sample_count: + self.handle_break(rxtx) + self.break_start[rxtx] = None + def decode(self): if not self.samplerate: raise SamplerateError('Cannot decode without samplerate.') @@ -383,18 +417,36 @@ class Decoder(srd.Decoder): opt = self.options inv = [opt['invert_rx'] == 'yes', opt['invert_tx'] == 'yes'] - cond_idx = [None] * len(has_pin) + cond_data_idx = [None] * len(has_pin) + + # Determine the number of samples for a complete frame's time span. + # A period of low signal (at least) that long is a break condition. + frame_samples = 1 # START + frame_samples += self.options['num_data_bits'] + frame_samples += 0 if self.options['parity_type'] == 'none' else 1 + frame_samples += self.options['num_stop_bits'] + frame_samples *= self.bit_width + self.break_min_sample_count = ceil(frame_samples) + cond_edge_idx = [None] * len(has_pin) while True: conds = [] if has_pin[RX]: - cond_idx[RX] = len(conds) + cond_data_idx[RX] = len(conds) conds.append(self.get_wait_cond(RX, inv[RX])) + cond_edge_idx[RX] = len(conds) + conds.append({RX: 'e'}) if has_pin[TX]: - cond_idx[TX] = len(conds) + cond_data_idx[TX] = len(conds) conds.append(self.get_wait_cond(TX, inv[TX])) + cond_edge_idx[TX] = len(conds) + conds.append({TX: 'e'}) (rx, tx) = self.wait(conds) - if cond_idx[RX] is not None and self.matched[cond_idx[RX]]: + if cond_data_idx[RX] is not None and self.matched[cond_data_idx[RX]]: self.inspect_sample(RX, rx, inv[RX]) - if cond_idx[TX] is not None and self.matched[cond_idx[TX]]: + if cond_edge_idx[RX] is not None and self.matched[cond_edge_idx[RX]]: + self.inspect_edge(RX, rx, inv[RX]) + if cond_data_idx[TX] is not None and self.matched[cond_data_idx[TX]]: self.inspect_sample(TX, tx, inv[TX]) + if cond_edge_idx[TX] is not None and self.matched[cond_edge_idx[TX]]: + self.inspect_edge(TX, tx, inv[TX]) |