X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=decoders%2Fusb_signalling%2Fpd.py;h=d2a1e8add21a7fd0ff9f7b0b0fc254065db579cd;hb=9059125f3997a7ce77ef5081da5e8bc8160e6769;hp=44aaaca1d8135d487788a90f9acd47edc28e5545;hpb=edad813467a4a248edaa1c91377d532b2e7f8786;p=libsigrokdecode.git diff --git a/decoders/usb_signalling/pd.py b/decoders/usb_signalling/pd.py index 44aaaca..d2a1e8a 100644 --- a/decoders/usb_signalling/pd.py +++ b/decoders/usb_signalling/pd.py @@ -23,6 +23,27 @@ import sigrokdecode as srd +''' +Protocol output format: + +Packet: +[, ] + +, : + - 'SOP', None + - 'SYM', + - 'BIT', + - 'STUFF BIT', None + - 'EOP', None + +: + - 'J', 'K', 'SE0', or 'SE1' + +: + - 0 or 1 + - Note: Symbols like SE0, SE1, and the J that's part of EOP don't yield 'BIT'. +''' + # Low-/full-speed symbols. # Note: Low-speed J and K are inverted compared to the full-speed J and K! symbols = { @@ -65,19 +86,18 @@ class Decoder(srd.Decoder): 'signalling': ['Signalling', 'full-speed'], } annotations = [ - ['symbol', 'Symbol'], + ['sym', 'Symbol'], ['sop', 'Start of packet (SOP)'], ['eop', 'End of packet (EOP)'], ['bit', 'Bit'], ['stuffbit', 'Stuff bit'], - ['packet', 'Packet'], ] def __init__(self): self.oldsym = 'J' # The "idle" state is J. - self.ss_sop = -1 + self.ss_sop = None + self.ss_block = None self.samplenum = 0 - self.packet = '' self.syms = [] self.bitrate = None self.bitwidth = None @@ -92,6 +112,7 @@ class Decoder(srd.Decoder): self.out_ann = self.add(srd.OUTPUT_ANN, 'usb_signalling') self.bitrate = bitrates[self.options['signalling']] self.bitwidth = float(metadata['samplerate']) / float(self.bitrate) + self.halfbit = int(self.bitwidth / 2) def report(self): pass @@ -102,13 +123,21 @@ class Decoder(srd.Decoder): def putx(self, data): self.put(self.samplenum, self.samplenum, self.out_ann, data) + def putpm(self, data): + s, h = self.samplenum, self.halfbit + self.put(self.ss_block - h, s + h, self.out_proto, data) + + def putm(self, data): + s, h = self.samplenum, self.halfbit + self.put(self.ss_block - h, s + h, self.out_ann, data) + def putpb(self, data): - s, halfbit = self.samplenum, int(self.bitwidth / 2) - self.put(s - halfbit, s + halfbit, self.out_proto, data) + s, h = self.samplenum, self.halfbit + self.put(s - h, s + h, self.out_proto, data) def putb(self, data): - s, halfbit = self.samplenum, int(self.bitwidth / 2) - self.put(s - halfbit, s + halfbit, self.out_ann, data) + s, h = self.samplenum, self.halfbit + self.put(s - h, s + h, self.out_ann, data) def set_new_target_samplenum(self): bitpos = self.ss_sop + (self.bitwidth / 2) @@ -128,13 +157,14 @@ class Decoder(srd.Decoder): def handle_bit(self, sym, b): if self.consecutive_ones == 6 and b == '0': - # Stuff bit. Don't add to the packet, reset self.consecutive_ones. + # Stuff bit. + self.putpb(['STUFF BIT', None]) self.putb([4, ['SB: %s/%s' % (sym, b)]]) self.consecutive_ones = 0 else: - # Normal bit. Add it to the packet, update self.consecutive_ones. + # Normal bit (not a stuff bit). + self.putpb(['BIT', b]) self.putb([3, ['%s/%s' % (sym, b)]]) - self.packet += b if b == '1': self.consecutive_ones += 1 else: @@ -149,16 +179,17 @@ class Decoder(srd.Decoder): self.set_new_target_samplenum() self.oldsym = sym if self.syms[-2:] == ['SE0', 'J']: - # Got an EOP, i.e. we now have a full packet. - self.putpb(['PACKET', self.packet]) - self.putb([5, ['PACKET: %s' % self.packet]]) - self.bitnum, self.packet, self.syms, self.state = 0, '', [], 'IDLE' + # Got an EOP. + self.putpm(['EOP', None]) + self.putm([2, ['EOP']]) + self.bitnum, self.syms, self.state = 0, [], 'IDLE' self.consecutive_ones = 0 def get_bit(self, sym): if sym == 'SE0': # Start of an EOP. Change state, run get_eop() for this bit. self.state = 'GET EOP' + self.ss_block = self.samplenum self.get_eop(sym) return self.syms.append(sym)