diff options
Diffstat (limited to 'decoders/onewire_link')
| -rw-r--r-- | decoders/onewire_link/pd.py | 63 |
1 files changed, 32 insertions, 31 deletions
diff --git a/decoders/onewire_link/pd.py b/decoders/onewire_link/pd.py index 03a6172..ca32415 100644 --- a/decoders/onewire_link/pd.py +++ b/decoders/onewire_link/pd.py @@ -89,7 +89,7 @@ timing = { } class Decoder(srd.Decoder): - api_version = 2 + api_version = 3 id = 'onewire_link' name = '1-Wire link layer' longname = '1-Wire serial communication bus (link layer)' @@ -119,7 +119,6 @@ class Decoder(srd.Decoder): def __init__(self): self.samplerate = None - self.samplenum = 0 self.state = 'INITIAL' self.present = 0 self.bit = 0 @@ -177,24 +176,28 @@ class Decoder(srd.Decoder): return self.samplerate = value - def decode(self, ss, es, data): + def wait_falling_timeout(self, start, t): + # Wait until either a falling edge is seen, and/or the specified + # number of samples have been skipped (i.e. time has passed). + cnt = int((t[self.overdrive] / 1000000.0) * self.samplerate) + samples_to_skip = (start + cnt) - self.samplenum + samples_to_skip = samples_to_skip if (samples_to_skip > 0) else 0 + return self.wait([{0: 'f'}, {'skip': samples_to_skip}]) + + def decode(self): if not self.samplerate: raise SamplerateError('Cannot decode without samplerate.') - for (self.samplenum, (owr,)) in data: - if self.samplenum == 0: - self.checks() - + self.checks() + while True: # State machine. if self.state == 'INITIAL': # Unknown initial state. # Wait until we reach the idle high state. - if owr == 0: - continue + self.wait({0: 'h'}) self.rise = self.samplenum self.state = 'IDLE' elif self.state == 'IDLE': # Idle high state. # Wait for falling edge. - if owr != 0: - continue + self.wait({0: 'f'}) self.fall = self.samplenum # Get time since last rising edge. time = ((self.fall - self.rise) / self.samplerate) * 1000000.0 @@ -208,8 +211,7 @@ class Decoder(srd.Decoder): # TODO: Check minimum recovery time. elif self.state == 'LOW': # Reset pulse or slot. # Wait for rising edge. - if owr == 0: - continue + self.wait({0: 'r'}) self.rise = self.samplenum # Detect reset or slot base on timing. time = ((self.rise - self.fall) / self.samplerate) * 1000000.0 @@ -248,11 +250,14 @@ class Decoder(srd.Decoder): self.putfr([1, ['Erroneous signal', 'Error', 'Err', 'E']]) self.state = 'IDLE' elif self.state == 'PRESENCE DETECT HIGH': # Wait for slave presence signal. + # Wait for a falling edge and/or presence detect signal. + self.wait_falling_timeout(self.rise, timing['PDH']['max']) + # Calculate time since rising edge. time = ((self.samplenum - self.rise) / self.samplerate) * 1000000.0 - if owr != 0 and time < timing['PDH']['max'][self.overdrive]: - continue - elif owr == 0: # Presence detected. + + if self.matched[0] and not self.matched[1]: + # Presence detected. if time < timing['PDH']['min'][self.overdrive]: self.putrs([1, ['Presence detect signal is too early', 'Presence detect too early', @@ -265,8 +270,7 @@ class Decoder(srd.Decoder): self.state = 'IDLE' elif self.state == 'PRESENCE DETECT LOW': # Slave presence signalled. # Wait for end of presence signal (on rising edge). - if owr == 0: - continue + self.wait({0: 'r'}) # Calculate time since start of presence signal. time = ((self.samplenum - self.fall) / self.samplerate) * 1000000.0 if time < timing['PDL']['min'][self.overdrive]: @@ -284,12 +288,11 @@ class Decoder(srd.Decoder): # End states (for additional checks). if self.state == 'SLOT': # Wait for end of time slot. - # Calculate time since falling edge. - time = ((self.samplenum - self.fall) / self.samplerate) * 1000000.0 - if owr != 0 and time < timing['SLOT']['min'][self.overdrive]: - continue - elif owr == 0: # Low detected before end of slot. - # Warn about irregularity. + # Wait for a falling edge and/or end of timeslot. + self.wait_falling_timeout(self.fall, timing['SLOT']['min']) + + if self.matched[0] and not self.matched[1]: + # Low detected before end of slot. self.putfs([1, ['Time slot not long enough', 'Slot too short', 'SLOT < ' + str(timing['SLOT']['min'][self.overdrive])]]) @@ -315,13 +318,11 @@ class Decoder(srd.Decoder): self.state = 'IDLE' if self.state == 'PRESENCE DETECT': - # Wait for end of presence detect. - # Calculate time since falling edge. - time = ((self.samplenum - self.rise) / self.samplerate) * 1000000.0 - if owr != 0 and time < timing['RSTH']['min'][self.overdrive]: - continue - elif owr == 0: # Low detected before end of presence detect. - # Warn about irregularity. + # Wait for a falling edge and/or end of presence detect. + self.wait_falling_timeout(self.rise, timing['RSTH']['min']) + + if self.matched[0] and not self.matched[1]: + # Low detected before end of presence detect. self.putfs([1, ['Presence detect not long enough', 'Presence detect too short', 'RTSH < ' + str(timing['RSTH']['min'][self.overdrive])]]) |