diff options
| -rw-r--r-- | decoders/uart/pd.py | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/decoders/uart/pd.py b/decoders/uart/pd.py index 4ce6ef9..9ffcb56 100644 --- a/decoders/uart/pd.py +++ b/decoders/uart/pd.py @@ -114,6 +114,7 @@ class Decoder(srd.Decoder): 'values': ('yes', 'no')}, {'id': 'invert_tx', 'desc': 'Invert TX', 'default': 'no', 'values': ('yes', 'no')}, + {'id': 'sample_point', 'desc': 'Sample point (%)', 'default': 50}, {'id': 'rx_packet_delim', 'desc': 'RX packet delimiter (decimal)', 'default': -1}, {'id': 'tx_packet_delim', 'desc': 'TX packet delimiter (decimal)', @@ -224,12 +225,15 @@ class Decoder(srd.Decoder): def get_sample_point(self, rxtx, bitnum): # Determine absolute sample number of a bit slot's sample point. - # bitpos is the samplenumber which is in the middle of the - # specified UART bit (0 = start bit, 1..x = data, x+1 = parity bit - # (if used) or the first stop bit, and so on). - # The samples within bit are 0, 1, ..., (bit_width - 1), therefore - # index of the middle sample within bit window is (bit_width - 1) / 2. - bitpos = self.frame_start[rxtx] + (self.bit_width - 1) / 2.0 + # Counts for UART bits start from 0 (0 = start bit, 1..x = data, + # x+1 = parity bit (if used) or the first stop bit, and so on). + # Accept a position in the range of 1.99% of the full bit width. + # Assume 50% for invalid input specs for backwards compatibility. + perc = self.options['sample_point'] or 50 + if not perc or perc not in range(1, 100): + perc = 50 + bitpos = (self.bit_width - 1) * perc / 100 + bitpos += self.frame_start[rxtx] bitpos += bitnum * self.bit_width return bitpos |