From 711d0602317e28ddc123ab540036b37979df70c4 Mon Sep 17 00:00:00 2001 From: Gerhard Sittig Date: Sun, 16 Oct 2016 18:26:18 +0200 Subject: uart: skip frames with invalid start bits When the start bit is not low at its sample point, then stop trying to interpret the remaining frame -- it's already known to be invalid, anyway. Wait for the next start bit instead, assuming that either the falling edge which started the inspection of the UART frame and its start bit was a spurious glitch or that the captured signal does not communicate at the decoder's configured bitrate. Signed-off-by: Gerhard Sittig --- decoders/uart/pd.py | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'decoders/uart') diff --git a/decoders/uart/pd.py b/decoders/uart/pd.py index af773b4..093f3fc 100644 --- a/decoders/uart/pd.py +++ b/decoders/uart/pd.py @@ -223,11 +223,13 @@ class Decoder(srd.Decoder): self.startbit[rxtx] = signal - # The startbit must be 0. If not, we report an error. + # The startbit must be 0. If not, we report an error and wait + # for the next start bit (assuming this one was spurious). if self.startbit[rxtx] != 0: self.putp(['INVALID STARTBIT', rxtx, self.startbit[rxtx]]) self.putg([rxtx + 10, ['Frame error', 'Frame err', 'FE']]) - # TODO: Abort? Ignore rest of the frame? + self.state[rxtx] = 'WAIT FOR START BIT' + return self.cur_data_bit[rxtx] = 0 self.datavalue[rxtx] = 0 -- cgit v1.2.3-70-g09d2