diff options
| -rw-r--r-- | decoders/jitter/pd.py | 103 |
1 files changed, 56 insertions, 47 deletions
diff --git a/decoders/jitter/pd.py b/decoders/jitter/pd.py index bc5164d..b6564ad 100644 --- a/decoders/jitter/pd.py +++ b/decoders/jitter/pd.py @@ -105,6 +105,60 @@ class Decoder(srd.Decoder): def putm(self, data): self.put(self.samplenum, self.samplenum, self.out_ann, data) + def handle_clk(self, clk, sig): + if self.clk_start == self.samplenum: + # Clock transition already treated. + # We have done everything we can with this sample. + return True + + if self.clk_edge(self.oldclk, clk): + # Clock edge found. + # We note the sample and move to the next state. + self.clk_start = self.samplenum + self.state = 'SIG' + return False + else: + if self.sig_start is not None \ + and self.sig_start != self.samplenum \ + and self.sig_edge(self.oldsig, sig): + # If any transition in the resulting signal + # occurs while we are waiting for a clock, + # we increase the missed signal counter. + self.sig_missed += 1 + self.put(ss, self.samplenum, self.out_sig_missed, self.sig_missed) + self.putm([2, ['Missed signal', 'MS']]) + # No clock edge found, we have done everything we + # can with this sample. + return True + + def handle_sig(self, clk, sig): + if self.sig_start == self.samplenum: + # Signal transition already treated. + # We have done everything we can with this sample. + return True + + if self.sig_edge(self.oldsig, sig): + # Signal edge found. + # We note the sample, calculate the jitter + # and move to the next state. + self.sig_start = self.samplenum + self.state = 'CLK' + # Calculate and report the timing jitter. + self.putx((self.sig_start - self.clk_start) / self.samplerate) + return False + else: + if self.clk_start != self.samplenum \ + and self.clk_edge(self.oldclk, clk): + # If any transition in the clock signal + # occurs while we are waiting for a resulting + # signal, we increase the missed clock counter. + self.clk_missed += 1 + self.put(ss, self.samplenum, self.out_clk_missed, self.clk_missed) + self.putm([1, ['Missed clock', 'MC']]) + # No resulting signal edge found, we have done + # everything we can with this sample. + return True + def decode(self, ss, es, data): if not self.samplerate: raise SamplerateError('Cannot decode without samplerate.') @@ -122,58 +176,13 @@ class Decoder(srd.Decoder): # State machine: # For each sample we can move 2 steps forward in the state machine. while True: - # Clock state has the lead. if self.state == 'CLK': - if self.clk_start == self.samplenum: - # Clock transition already treated. - # We have done everything we can with this sample. + if self.handle_clk(clk, sig): break - else: - if self.clk_edge(self.oldclk, clk) is True: - # Clock edge found. - # We note the sample and move to the next state. - self.clk_start = self.samplenum - self.state = 'SIG' - else: - if self.sig_start is not None \ - and self.sig_start != self.samplenum \ - and self.sig_edge(self.oldsig, sig) is True: - # If any transition in the resulting signal - # occurs while we are waiting for a clock, - # we increase the missed signal counter. - self.sig_missed += 1 - self.put(ss, self.samplenum, self.out_sig_missed, self.sig_missed) - self.putm([2, ['Missed signal', 'MS']]) - # No clock edge found, we have done everything we - # can with this sample. - break if self.state == 'SIG': - if self.sig_start == self.samplenum: - # Signal transition already treated. - # We have done everything we can with this sample. + if self.handle_sig(clk, sig): break - else: - if self.sig_edge(self.oldsig, sig) is True: - # Signal edge found. - # We note the sample, calculate the jitter - # and move to the next state. - self.sig_start = self.samplenum - self.state = 'CLK' - # Calculate and report the timing jitter. - self.putx((self.sig_start - self.clk_start) / self.samplerate) - else: - if self.clk_start != self.samplenum \ - and self.clk_edge(self.oldclk, clk) is True: - # If any transition in the clock signal - # occurs while we are waiting for a resulting - # signal, we increase the missed clock counter. - self.clk_missed += 1 - self.put(ss, self.samplenum, self.out_clk_missed, self.clk_missed) - self.putm([1, ['Missed clock', 'MC']]) - # No resulting signal edge found, we have done - # everything we can with this sample. - break # Save current CLK/SIG values for the next round. self.oldclk, self.oldsig = clk, sig |