## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
-# CAN protocol decoder
-
import sigrokdecode as srd
+class SamplerateError(Exception):
+ pass
+
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 2
id = 'can'
name = 'CAN'
longname = 'Controller Area Network'
license = 'gplv2+'
inputs = ['logic']
outputs = ['can']
- probes = [
+ channels = (
{'id': 'can_rx', 'name': 'CAN RX', 'desc': 'CAN bus line'},
- ]
- optional_probes = []
- options = {
- 'bitrate': ['Bitrate', 1000000], # 1Mbit/s
- 'sample_point': ['Sample point', 70], # 70%
- }
- annotations = [
- ['Text', 'Human-readable text'],
- ['Warnings', 'Human-readable warnings'],
- ]
+ )
+ options = (
+ {'id': 'bitrate', 'desc': 'Bitrate (bits/s)', 'default': 1000000},
+ {'id': 'sample_point', 'desc': 'Sample point (%)', 'default': 70.0},
+ )
+ annotations = (
+ ('data', 'CAN payload data'),
+ ('sof', 'Start of frame'),
+ ('eof', 'End of frame'),
+ ('id', 'Identifier'),
+ ('ext-id', 'Extended identifier'),
+ ('full-id', 'Full identifier'),
+ ('ide', 'Identifier extension bit'),
+ ('reserved-bit', 'Reserved bit 0 and 1'),
+ ('rtr', 'Remote transmission request'),
+ ('srr', 'Substitute remote request'),
+ ('dlc', 'Data length count'),
+ ('crc-sequence', 'CRC sequence'),
+ ('crc-delimiter', 'CRC delimiter'),
+ ('ack-slot', 'ACK slot'),
+ ('ack-delimiter', 'ACK delimiter'),
+ ('stuff-bit', 'Stuff bit'),
+ ('warnings', 'Human-readable warnings'),
+ )
def __init__(self, **kwargs):
+ self.samplerate = None
self.reset_variables()
- def start(self, metadata):
- # self.out_proto = self.add(srd.OUTPUT_PROTO, 'can')
- self.out_ann = self.add(srd.OUTPUT_ANN, 'can')
-
- self.samplerate = metadata['samplerate']
- self.bit_width = float(self.samplerate) / float(self.options['bitrate'])
- self.bitpos = (self.bit_width / 100.0) * self.options['sample_point']
+ def start(self):
+ self.out_ann = self.register(srd.OUTPUT_ANN)
- def report(self):
- pass
+ 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.bitpos = (self.bit_width / 100.0) * self.options['sample_point']
# Generic helper for CAN bit annotations.
def putg(self, ss, es, data):
return False
# Stuff bit. Keep it in self.rawbits, but drop it from self.bits.
- self.putx([0, ['Stuff bit: %d' % self.rawbits[-1]]])
+ self.putx([15, ['Stuff bit: %d' % self.rawbits[-1],
+ 'SB: %d' % self.rawbits[-1], 'SB']])
self.bits.pop() # Drop last bit.
return True
x = self.last_databit + 1
crc_bits = self.bits[x:x + 15 + 1]
self.crc = int(''.join(str(d) for d in crc_bits), 2)
- self.putb([0, ['CRC: 0x%04x' % self.crc]])
+ self.putb([11, ['CRC sequence: 0x%04x' % self.crc,
+ 'CRC: 0x%04x' % self.crc, 'CRC']])
if not self.is_valid_crc(crc_bits):
- self.putb([0, ['CRC is invalid']])
+ self.putb([16, ['CRC is invalid']])
# CRC delimiter bit (recessive)
elif bitnum == (self.last_databit + 16):
- self.putx([0, ['CRC delimiter: %d' % can_rx]])
+ self.putx([12, ['CRC delimiter: %d' % can_rx,
+ 'CRC d: %d' % can_rx, 'CRC d']])
# ACK slot bit (dominant: ACK, recessive: NACK)
elif bitnum == (self.last_databit + 17):
ack = 'ACK' if can_rx == 0 else 'NACK'
- self.putx([0, ['ACK slot: %s' % ack]])
+ self.putx([13, ['ACK slot: %s' % ack, 'ACK s: %s' % ack, 'ACK s']])
# ACK delimiter bit (recessive)
elif bitnum == (self.last_databit + 18):
- self.putx([0, ['ACK delimiter: %d' % can_rx]])
+ self.putx([14, ['ACK delimiter: %d' % can_rx,
+ 'ACK d: %d' % can_rx, 'ACK d']])
# Remember start of EOF (see below).
elif bitnum == (self.last_databit + 19):
# End of frame (EOF), 7 recessive bits
elif bitnum == (self.last_databit + 25):
- self.putb([0, ['End of frame', 'EOF']])
+ self.putb([2, ['End of frame', 'EOF', 'E']])
self.reset_variables()
return True
# Bit 14: RB0 (reserved bit)
# Has to be sent dominant, but receivers should accept recessive too.
if bitnum == 14:
- self.putx([0, ['RB0: %d' % can_rx]])
+ self.putx([7, ['Reserved bit 0: %d' % can_rx,
+ 'RB0: %d' % can_rx, 'RB0']])
# Bit 12: Remote transmission request (RTR) bit
# Data frame: dominant, remote frame: recessive
# Remote frames do not contain a data field.
rtr = 'remote' if self.bits[12] == 1 else 'data'
- self.put12([0, ['RTR: %s frame' % rtr]])
+ self.put12([8, ['Remote transmission request: %s frame' % rtr,
+ 'RTR: %s frame' % rtr, 'RTR']])
# Remember start of DLC (see below).
elif bitnum == 15:
# 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)
- self.putb([0, ['DLC: %d' % self.dlc]])
+ self.putb([10, ['Data length code: %d' % self.dlc,
+ 'DLC: %d' % self.dlc, 'DLC']])
self.last_databit = 18 + (self.dlc * 8)
# Remember all databyte bits, except the very last one.
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]
- self.putg(ss, es, [0, ['Data byte %d: 0x%02x' % (i, b)]])
+ self.putg(ss, es, [0, ['Data byte %d: 0x%02x' % (i, b),
+ 'DB %d: 0x%02x' % (i, b), 'DB']])
self.ss_databytebits = []
elif bitnum > self.last_databit:
# Bits 14-31: Extended identifier (EID[17..0])
elif bitnum == 31:
self.eid = int(''.join(str(d) for d in self.bits[14:]), 2)
- self.putb([0, ['Extended ID: %d (0x%x)' % (self.eid, self.eid)]])
+ s = '%d (0x%x)' % (self.eid, self.eid)
+ self.putb([4, ['Extended Identifier: %s' % s,
+ 'Extended ID: %s' % s, 'Extended ID', 'EID']])
self.fullid = self.id << 18 | self.eid
- self.putb([0, ['Full ID: %d (0x%x)' % (self.fullid, self.fullid)]])
+ s = '%d (0x%x)' % (self.fullid, self.fullid)
+ self.putb([5, ['Full Identifier: %s' % s, 'Full ID: %s' % s,
+ 'Full ID', 'FID']])
# Bit 12: Substitute remote request (SRR) bit
- self.put12([0, ['SRR: %d' % self.bits[12]]])
+ self.put12([9, ['Substitute remote request: %d' % self.bits[12],
+ 'SRR: %d' % self.bits[12], 'SRR']])
# Bit 32: Remote transmission request (RTR) bit
# Data frame: dominant, remote frame: recessive
# Remote frames do not contain a data field.
if bitnum == 32:
rtr = 'remote' if can_rx == 1 else 'data'
- self.putx([0, ['RTR: %s frame' % rtr]])
+ self.putx([8, ['Remote transmission request: %s frame' % rtr,
+ 'RTR: %s frame' % rtr, 'RTR']])
# Bit 33: RB1 (reserved bit)
elif bitnum == 33:
- self.putx([0, ['RB1: %d' % can_rx]])
+ self.putx([7, ['Reserved bit 1: %d' % can_rx,
+ 'RB1: %d' % can_rx, 'RB1']])
# Bit 34: RB0 (reserved bit)
elif bitnum == 34:
- self.putx([0, ['RB0: %d' % can_rx]])
+ self.putx([7, ['Reserved bit 0: %d' % can_rx,
+ 'RB0: %d' % can_rx, 'RB0']])
# Remember start of DLC (see below).
elif bitnum == 35:
# 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)
- self.putb([0, ['DLC: %d' % self.dlc]])
+ self.putb([10, ['Data length code: %d' % self.dlc,
+ 'DLC: %d' % self.dlc, 'DLC']])
self.last_databit = 38 + (self.dlc * 8)
# Remember all databyte bits, except the very last one.
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]
- self.putg(ss, es, [0, ['Data byte %d: 0x%02x' % (i, b)]])
+ self.putg(ss, es, [0, ['Data byte %d: 0x%02x' % (i, b),
+ 'DB %d: 0x%02x' % (i, b), 'DB']])
self.ss_databytebits = []
elif bitnum > self.last_databit:
# Bit 0: Start of frame (SOF) bit
if bitnum == 0:
if can_rx == 0:
- self.putx([0, ['Start of frame', 'SOF']])
+ self.putx([1, ['Start of frame', 'SOF', 'S']])
else:
- self.putx([1, ['Start of frame (SOF) must be a dominant bit']])
+ self.putx([16, ['Start of frame (SOF) must be a dominant bit']])
# Remember start of ID (see below).
elif bitnum == 1:
# The bits ID[10..4] must NOT be all recessive.
elif bitnum == 11:
self.id = int(''.join(str(d) for d in self.bits[1:]), 2)
- self.putb([0, ['ID: %d (0x%x)' % (self.id, self.id)]])
+ s = '%d (0x%x)' % (self.id, self.id),
+ self.putb([3, ['Identifier: %s' % s, 'ID: %s' % s, 'ID']])
# RTR or SRR bit, depending on frame type (gets handled later).
elif bitnum == 12:
# Standard frame: dominant, extended frame: recessive
elif bitnum == 13:
ide = self.frame_type = 'standard' if can_rx == 0 else 'extended'
- self.putx([0, ['IDE: %s frame' % ide]])
+ self.putx([6, ['Identifier extension bit: %s frame' % ide,
+ 'IDE: %s frame' % ide, 'IDE']])
# Bits 14-X: Frame-type dependent, passed to the resp. handlers.
elif bitnum >= 14:
self.curbit += 1
def decode(self, ss, es, data):
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
for (self.samplenum, pins) in data:
(can_rx,) = pins
if not self.reached_bit(self.curbit):
continue
self.handle_bit(can_rx)
- else:
- raise Exception("Invalid state: %s" % self.state)
-