X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decoders%2Fcan%2Fpd.py;h=3ab82b02c054dea02f0c5b4b7c0fbac0564f2917;hp=3749afef4d46b9b45c9e623d03c0d6956ff6ab0c;hb=8abd7aa36c1a8c2d83777fedba499f6fb7f38e06;hpb=38b40330850f81eef9669223f39633a649d98f2a diff --git a/decoders/can/pd.py b/decoders/can/pd.py index 3749afe..3ab82b0 100644 --- a/decoders/can/pd.py +++ b/decoders/can/pd.py @@ -23,6 +23,9 @@ import sigrokdecode as srd class SamplerateError(Exception): pass +def dlc2len(dlc): + return [0, 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 48, 64][dlc] + class Decoder(srd.Decoder): api_version = 3 id = 'can' @@ -37,7 +40,8 @@ class Decoder(srd.Decoder): {'id': 'can_rx', 'name': 'CAN RX', 'desc': 'CAN bus line'}, ) options = ( - {'id': 'bitrate', 'desc': 'Bitrate (bits/s)', 'default': 1000000}, + {'id': 'nominal_bitrate', 'desc': 'Nominal bitrate (bits/s)', 'default': 1000000}, + {'id': 'fast_bitrate', 'desc': 'Fast bitrate (bits/s)', 'default': 2000000}, {'id': 'sample_point', 'desc': 'Sample point (%)', 'default': 70.0}, ) annotations = ( @@ -76,10 +80,20 @@ class Decoder(srd.Decoder): def start(self): self.out_ann = self.register(srd.OUTPUT_ANN) + def set_bit_rate(self, bitrate): + self.bit_width = float(self.samplerate) / float(bitrate) + self.sample_point = (self.bit_width / 100.0) * self.options['sample_point'] + + def set_nominal_bitrate(self): + self.set_bit_rate(self.options['nominal_bitrate']) + + def set_fast_bitrate(self): + self.set_bit_rate(self.options['fast_bitrate']) + def metadata(self, key, value): if key == srd.SRD_CONF_SAMPLERATE: self.samplerate = value - self.bit_width = float(self.samplerate) / float(self.options['bitrate']) + self.bit_width = float(self.samplerate) / float(self.options['nominal_bitrate']) self.sample_point = (self.bit_width / 100.0) * self.options['sample_point'] # Generic helper for CAN bit annotations. @@ -95,6 +109,10 @@ class Decoder(srd.Decoder): def put12(self, data): self.putg(self.ss_bit12, self.ss_bit12, data) + # Single-CAN-bit annotation using the samplenum of CAN bit 32. + def put32(self, data): + self.putg(self.ss_bit32, self.ss_bit32, data) + # Multi-CAN-bit annotation from self.ss_block to current samplenum. def putb(self, data): self.putg(self.ss_block, self.samplenum, data) @@ -108,7 +126,10 @@ class Decoder(srd.Decoder): self.last_databit = 999 # Positive value that bitnum+x will never match self.ss_block = None self.ss_bit12 = None + self.ss_bit32 = None self.ss_databytebits = [] + self.fd = False + self.rtr = None # Poor man's clock synchronization. Use signal edges which change to # dominant state in rather simple ways. This naive approach is neither @@ -161,42 +182,60 @@ class Decoder(srd.Decoder): # Remember start of CRC sequence (see below). if bitnum == (self.last_databit + 1): self.ss_block = self.samplenum + if self.fd: + if dlc2len(self.dlc) < 16: + self.crc_len = 27 # 17 + SBC + stuff bits + else: + self.crc_len = 32 # 21 + SBC + stuff bits + else: + self.crc_len = 15 + + # CRC sequence (15 bits, 17 bits or 21 bits) + elif bitnum == (self.last_databit + self.crc_len): + if self.fd: + if dlc2len(self.dlc) < 16: + crc_type = "CRC-17" + else: + crc_type = "CRC-21" + else: + crc_type = "CRC-15" - # CRC sequence (15 bits) - elif bitnum == (self.last_databit + 15): x = self.last_databit + 1 - crc_bits = self.bits[x:x + 15 + 1] + crc_bits = self.bits[x:x + self.crc_len + 1] self.crc = int(''.join(str(d) for d in crc_bits), 2) - self.putb([11, ['CRC sequence: 0x%04x' % self.crc, - 'CRC: 0x%04x' % self.crc, 'CRC']]) + self.putb([11, ['%s sequence: 0x%04x' % (crc_type, self.crc), + '%s: 0x%04x' % (crc_type, self.crc), '%s' % crc_type]]) if not self.is_valid_crc(crc_bits): self.putb([16, ['CRC is invalid']]) # CRC delimiter bit (recessive) - elif bitnum == (self.last_databit + 16): + elif bitnum == (self.last_databit + self.crc_len + 1): self.putx([12, ['CRC delimiter: %d' % can_rx, 'CRC d: %d' % can_rx, 'CRC d']]) if can_rx != 1: self.putx([16, ['CRC delimiter must be a recessive bit']]) + if self.fd: + self.set_nominal_bitrate() + # ACK slot bit (dominant: ACK, recessive: NACK) - elif bitnum == (self.last_databit + 17): + elif bitnum == (self.last_databit + self.crc_len + 2): ack = 'ACK' if can_rx == 0 else 'NACK' self.putx([13, ['ACK slot: %s' % ack, 'ACK s: %s' % ack, 'ACK s']]) # ACK delimiter bit (recessive) - elif bitnum == (self.last_databit + 18): + elif bitnum == (self.last_databit + self.crc_len + 3): self.putx([14, ['ACK delimiter: %d' % can_rx, 'ACK d: %d' % can_rx, 'ACK d']]) if can_rx != 1: self.putx([16, ['ACK delimiter must be a recessive bit']]) # Remember start of EOF (see below). - elif bitnum == (self.last_databit + 19): + elif bitnum == (self.last_databit + self.crc_len + 4): self.ss_block = self.samplenum # End of frame (EOF), 7 recessive bits - elif bitnum == (self.last_databit + 25): + elif bitnum == (self.last_databit + self.crc_len + 10): self.putb([2, ['End of frame', 'EOF', 'E']]) if self.rawbits[-7:] != [1, 1, 1, 1, 1, 1, 1]: self.putb([16, ['End of frame (EOF) must be 7 recessive bits']]) @@ -208,17 +247,22 @@ class Decoder(srd.Decoder): # Returns True if the frame ended (EOF), False otherwise. def decode_standard_frame(self, can_rx, bitnum): - # Bit 14: FDF (Flexible Data Format) - # Has to be sent dominant when FD frame, has to be sent recessive when classic CAN frame. + # Bit 14: FDF (Flexible data format) + # Has to be sent dominant when FD frame, has to be sent recessive + # when classic CAN frame. if bitnum == 14: self.fd = True if can_rx else False + if self.fd: + self.putx([7, ['Flexible data format: %d' % can_rx, + 'FDF: %d' % can_rx, 'FDF']]) + else: + self.putx([7, ['Reserved bit 0: %d' % can_rx, + 'RB0: %d' % can_rx, 'RB0']]) - self.putx([7, ['Flexible Data Format: %d' % can_rx, - 'FDF: %d' % can_rx, 'FDF']]) - - # SRR Substitute Remote Request if self.fd: - self.put12([8, ['Substitute Remote Request', 'SRR']]) + # Bit 12: Substitute remote request (SRR) bit + self.put12([8, ['Substitute remote request', 'SRR']]) + self.dlc_start = 18 else: # Bit 12: Remote transmission request (RTR) bit # Data frame: dominant, remote frame: recessive @@ -226,33 +270,40 @@ class Decoder(srd.Decoder): rtr = 'remote' if self.bits[12] == 1 else 'data' self.put12([8, ['Remote transmission request: %s frame' % rtr, 'RTR: %s frame' % rtr, 'RTR']]) + self.dlc_start = 15 - # TODO: add Res, BRS and ESI bits when FD format: + if bitnum == 15 and self.fd: + self.putx([7, ['Reserved: %d' % can_rx, 'R0: %d' % can_rx, 'R0']]) + if bitnum == 16 and self.fd: + self.putx([7, ['Bit rate switch: %d' % can_rx, 'BRS: %d' % can_rx, 'BRS']]) + + if bitnum == 17 and self.fd: + self.putx([7, ['Error state indicator: %d' % can_rx, 'ESI: %d' % can_rx, 'ESI']]) # Remember start of DLC (see below). - elif bitnum == 15: + elif bitnum == self.dlc_start: self.ss_block = self.samplenum # Bits 15-18: Data length code (DLC), in number of bytes (0-8). - elif bitnum == 18: - self.dlc = int(''.join(str(d) for d in self.bits[15:18 + 1]), 2) + elif bitnum == self.dlc_start + 3: + self.dlc = int(''.join(str(d) for d in self.bits[self.dlc_start:self.dlc_start + 4]), 2) self.putb([10, ['Data length code: %d' % self.dlc, 'DLC: %d' % self.dlc, 'DLC']]) - self.last_databit = 18 + (self.dlc * 8) - if self.dlc > 8: + self.last_databit = self.dlc_start + 3 + (dlc2len(self.dlc) * 8) + if self.dlc > 8 and not self.fd: self.putb([16, ['Data length code (DLC) > 8 is not allowed']]) # Remember all databyte bits, except the very last one. - elif bitnum in range(19, self.last_databit): + elif bitnum in range(self.dlc_start + 4, self.last_databit): self.ss_databytebits.append(self.samplenum) # Bits 19-X: Data field (0-8 bytes, depending on DLC) # The bits within a data byte are transferred MSB-first. elif bitnum == self.last_databit: self.ss_databytebits.append(self.samplenum) # Last databyte bit. - for i in range(self.dlc): - x = 18 + (8 * i) + 1 + for i in range(dlc2len(self.dlc)): + x = self.dlc_start + 4 + (8 * i) b = int(''.join(str(d) for d in self.bits[x:x + 8]), 2) ss = self.ss_databytebits[i * 8] es = self.ss_databytebits[((i + 1) * 8) - 1] @@ -271,6 +322,8 @@ class Decoder(srd.Decoder): # Remember start of EID (see below). if bitnum == 14: self.ss_block = self.samplenum + self.fd = False + self.dlc_start = 35 # Bits 14-31: Extended identifier (EID[17..0]) elif bitnum == 31: @@ -291,42 +344,64 @@ class Decoder(srd.Decoder): # Bit 32: Remote transmission request (RTR) bit # Data frame: dominant, remote frame: recessive # Remote frames do not contain a data field. + + # Remember start of RTR (see below). if bitnum == 32: - rtr = 'remote' if can_rx == 1 else 'data' - self.putx([8, ['Remote transmission request: %s frame' % rtr, - 'RTR: %s frame' % rtr, 'RTR']]) + self.ss_bit32 = self.samplenum + self.rtr = can_rx + + if not self.fd: + rtr = 'remote' if can_rx == 1 else 'data' + self.putx([8, ['Remote transmission request: %s frame' % rtr, + 'RTR: %s frame' % rtr, 'RTR']]) # Bit 33: RB1 (reserved bit) elif bitnum == 33: - self.putx([7, ['Reserved bit 1: %d' % can_rx, - 'RB1: %d' % can_rx, 'RB1']]) + self.fd = True if can_rx else False + if self.fd: + self.dlc_start = 37 + self.putx([7, ['Flexible data format: %d' % can_rx, + 'FDF: %d' % can_rx, 'FDF']]) + self.put32([7, ['Reserved bit 1: %d' % self.rtr, + 'RB1: %d' % self.rtr, 'RB1']]) + else: + self.putx([7, ['Reserved bit 1: %d' % can_rx, + 'RB1: %d' % can_rx, 'RB1']]) # Bit 34: RB0 (reserved bit) elif bitnum == 34: self.putx([7, ['Reserved bit 0: %d' % can_rx, 'RB0: %d' % can_rx, 'RB0']]) + elif bitnum == 35 and self.fd: + self.putx([7, ['Bit rate switch: %d' % can_rx, + 'BRS: %d' % can_rx, 'BRS']]) + + elif bitnum == 36 and self.fd: + self.putx([7, ['Error state indicator: %d' % can_rx, + 'ESI: %d' % can_rx, 'ESI']]) + # Remember start of DLC (see below). - elif bitnum == 35: + elif bitnum == self.dlc_start: self.ss_block = self.samplenum # Bits 35-38: Data length code (DLC), in number of bytes (0-8). - elif bitnum == 38: - self.dlc = int(''.join(str(d) for d in self.bits[35:38 + 1]), 2) + elif bitnum == self.dlc_start + 3: + self.dlc = int(''.join(str(d) for d in self.bits[self.dlc_start:self.dlc_start + 4]), 2) self.putb([10, ['Data length code: %d' % self.dlc, 'DLC: %d' % self.dlc, 'DLC']]) - self.last_databit = 38 + (self.dlc * 8) + self.last_databit = self.dlc_start + 3 + (dlc2len(self.dlc) * 8) # Remember all databyte bits, except the very last one. - elif bitnum in range(39, self.last_databit): + elif bitnum in range(self.dlc_start + 4, self.last_databit): self.ss_databytebits.append(self.samplenum) # Bits 39-X: Data field (0-8 bytes, depending on DLC) # The bits within a data byte are transferred MSB-first. elif bitnum == self.last_databit: self.ss_databytebits.append(self.samplenum) # Last databyte bit. - for i in range(self.dlc): - x = 38 + (8 * i) + 1 + for i in range(dlc2len(self.dlc)): + x = self.dlc_start + 4 + (8 * i) b = int(''.join(str(d) for d in self.bits[x:x + 8]), 2) ss = self.ss_databytebits[i * 8] es = self.ss_databytebits[((i + 1) * 8) - 1] @@ -346,6 +421,12 @@ class Decoder(srd.Decoder): # Get the index of the current CAN frame bit (without stuff bits). bitnum = len(self.bits) - 1 + if self.fd and can_rx: + if bitnum == 16 and self.frame_type == 'standard' \ + or bitnum == 35 and self.frame_type == 'extended': + self.dom_edge_seen(force=True) + self.set_fast_bitrate() + # If this is a stuff bit, remove it from self.bits and ignore it. if self.is_stuff_bit(): self.putx([15, [str(can_rx)]]) @@ -387,8 +468,6 @@ class Decoder(srd.Decoder): # Bits 14-X: Frame-type dependent, passed to the resp. handlers. elif bitnum >= 14: - self.fd = True if can_rx else False - if self.frame_type == 'standard': done = self.decode_standard_frame(can_rx, bitnum) else: