diff options
Diffstat (limited to 'decoders/i2c')
| -rw-r--r-- | decoders/i2c/pd.py | 84 |
1 files changed, 56 insertions, 28 deletions
diff --git a/decoders/i2c/pd.py b/decoders/i2c/pd.py index 4d77920..2db7d21 100644 --- a/decoders/i2c/pd.py +++ b/decoders/i2c/pd.py @@ -1,7 +1,7 @@ ## ## This file is part of the libsigrokdecode project. ## -## Copyright (C) 2010-2013 Uwe Hermann <uwe@hermann-uwe.de> +## Copyright (C) 2010-2014 Uwe Hermann <uwe@hermann-uwe.de> ## ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by @@ -41,6 +41,7 @@ I²C packet: - 'STOP' (STOP condition) - 'ACK' (ACK bit) - 'NACK' (NACK bit) + - 'BITS' (<data>: list of data/address bits and their ss/es numbers) <data> is the data or address byte associated with the 'ADDRESS*' and 'DATA*' command. Slave addresses do not include bit 0 (the READ/WRITE indication bit). @@ -55,10 +56,11 @@ proto = { 'STOP': [2, 'Stop', 'P'], 'ACK': [3, 'ACK', 'A'], 'NACK': [4, 'NACK', 'N'], - 'ADDRESS READ': [5, 'Address read', 'AR'], - 'ADDRESS WRITE': [6, 'Address write', 'AW'], - 'DATA READ': [7, 'Data read', 'DR'], - 'DATA WRITE': [8, 'Data write', 'DW'], + 'BIT': [5, 'Bit', 'B'], + 'ADDRESS READ': [6, 'Address read', 'AR'], + 'ADDRESS WRITE': [7, 'Address write', 'AW'], + 'DATA READ': [8, 'Data read', 'DR'], + 'DATA WRITE': [9, 'Data write', 'DW'], } class Decoder(srd.Decoder): @@ -84,12 +86,18 @@ class Decoder(srd.Decoder): ['stop', 'Stop condition'], ['ack', 'ACK'], ['nack', 'NACK'], + ['bit', 'Data/address bit'], ['address-read', 'Address read'], ['address-write', 'Address write'], ['data-read', 'Data read'], ['data-write', 'Data write'], ['warnings', 'Human-readable warnings'], ] + annotation_rows = ( + ('bits', 'Bits', (5,)), + ('addr-data', 'Address/Data', (0, 1, 2, 3, 4, 6, 7, 8, 9)), + ('warnings', 'Warnings', (10,)), + ) binary = ( ('address-read', 'Address read'), ('address-write', 'Address write'), @@ -99,18 +107,18 @@ class Decoder(srd.Decoder): def __init__(self, **kwargs): self.samplerate = None - self.startsample = -1 + self.ss = self.es = self.byte_ss = -1 self.samplenum = None self.bitcount = 0 self.databyte = 0 self.wr = -1 self.is_repeat_start = 0 self.state = 'FIND START' - self.oldscl = 1 - self.oldsda = 1 + self.oldscl = self.oldsda = 1 self.oldpins = [1, 1] self.pdu_start = None self.pdu_bits = 0 + self.bits = [] def metadata(self, key, value): if key == srd.SRD_CONF_SAMPLERATE: @@ -124,13 +132,13 @@ class Decoder(srd.Decoder): meta=(int, 'Bitrate', 'Bitrate from Start bit to Stop bit')) def putx(self, data): - self.put(self.startsample, self.samplenum, self.out_ann, data) + self.put(self.ss, self.es, self.out_ann, data) def putp(self, data): - self.put(self.startsample, self.samplenum, self.out_python, data) + self.put(self.ss, self.es, self.out_python, data) def putb(self, data): - self.put(self.startsample, self.samplenum, self.out_binary, data) + self.put(self.ss, self.es, self.out_binary, data) def is_start_condition(self, scl, sda): # START condition (S): SDA = falling, SCL = high @@ -151,7 +159,7 @@ class Decoder(srd.Decoder): return False def found_start(self, scl, sda): - self.startsample = self.samplenum + self.ss, self.es = self.samplenum, self.samplenum self.pdu_start = self.samplenum self.pdu_bits = 0 cmd = 'START REPEAT' if (self.is_repeat_start == 1) else 'START' @@ -161,6 +169,7 @@ class Decoder(srd.Decoder): self.bitcount = self.databyte = 0 self.is_repeat_start = 1 self.wr = -1 + self.bits = [] # Gather 8 bits of data plus the ACK/NACK bit. def found_address_or_data(self, scl, sda): @@ -168,17 +177,24 @@ class Decoder(srd.Decoder): self.databyte <<= 1 self.databyte |= sda + # Remember the start of the first data/address bit. if self.bitcount == 0: - self.startsample = self.samplenum + self.byte_ss = self.samplenum + + # Store individual bits and their start/end samplenumbers. + # In the list, index 0 represents the LSB (I²C transmits MSB-first). + self.bits.insert(0, [sda, self.samplenum, self.samplenum]) + if self.bitcount > 0: + self.bits[1][2] = self.samplenum + if self.bitcount == 7: + self.bitwidth = self.bits[1][2] - self.bits[2][2] + self.bits[0][2] += self.bitwidth # Return if we haven't collected all 8 + 1 bits, yet. - self.bitcount += 1 - if self.bitcount != 8: + if self.bitcount < 7: + self.bitcount += 1 return - # We triggered on the ACK/NACK bit, but won't report that until later. - self.startsample -= 1 - d = self.databyte if self.state == 'FIND ADDRESS': # The READ/WRITE bit is only in address bytes, not data bytes. @@ -200,18 +216,32 @@ class Decoder(srd.Decoder): cmd = 'DATA READ' bin_class = 2 + self.ss, self.es = self.byte_ss, self.samplenum + self.bitwidth + + self.putp(['BITS', self.bits]) self.putp([cmd, d]) - self.putx([proto[cmd][0], ['%s: %02X' % (proto[cmd][1], d), - '%s: %02X' % (proto[cmd][2], d), '%02X' % d]]) + self.putb((bin_class, bytes([d]))) + for bit in self.bits: + self.put(bit[1], bit[2], self.out_ann, [5, ['%d' % bit[0]]]) + + if cmd.startswith('ADDRESS'): + self.ss, self.es = self.samplenum, self.samplenum + self.bitwidth + w = ['Write', 'Wr', 'W'] if self.wr else ['Read', 'Rd', 'R'] + self.putx([proto[cmd][0], w]) + self.ss, self.es = self.byte_ss, self.samplenum + + self.putx([proto[cmd][0], ['%s: %02X' % (proto[cmd][1], d), + '%s: %02X' % (proto[cmd][2], d), '%02X' % d]]) + # Done with this packet. - self.startsample = -1 self.bitcount = self.databyte = 0 + self.bits = [] self.state = 'FIND ACK' def get_ack(self, scl, sda): - self.startsample = self.samplenum + self.ss, self.es = self.samplenum, self.samplenum + self.bitwidth cmd = 'NACK' if (sda == 1) else 'ACK' self.putp([cmd, None]) self.putx([proto[cmd][0], proto[cmd][1:]]) @@ -223,15 +253,16 @@ class Decoder(srd.Decoder): # Meta bitrate elapsed = 1 / float(self.samplerate) * (self.samplenum - self.pdu_start + 1) bitrate = int(1 / elapsed * self.pdu_bits) - self.put(self.startsample, self.samplenum, self.out_bitrate, bitrate) + self.put(self.byte_ss, self.samplenum, self.out_bitrate, bitrate) - self.startsample = self.samplenum cmd = 'STOP' + self.ss, self.es = self.samplenum, self.samplenum self.putp([cmd, None]) self.putx([proto[cmd][0], proto[cmd][1:]]) self.state = 'FIND START' self.is_repeat_start = 0 self.wr = -1 + self.bits = [] def decode(self, ss, es, data): if self.samplerate is None: @@ -245,8 +276,6 @@ class Decoder(srd.Decoder): self.pdu_bits += 1 - # TODO: Wait until the bus is idle (SDA = SCL = 1) first? - # State machine. if self.state == 'FIND START': if self.is_start_condition(scl, sda): @@ -268,6 +297,5 @@ class Decoder(srd.Decoder): raise Exception('Invalid state: %s' % self.state) # Save current SDA/SCL values for the next round. - self.oldscl = scl - self.oldsda = sda + self.oldscl, self.oldsda = scl, sda |