## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
+## Copyright (C) 2019 Stephan Thiele <stephan.thiele@mailbox.org>
##
## 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
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
-## along with this program; if not, write to the Free Software
-## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
-# CAN protocol decoder
-
+from common.srdhelper import bitpack_msb
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 = 1
+ api_version = 3
id = 'can'
name = 'CAN'
longname = 'Controller Area Network'
license = 'gplv2+'
inputs = ['logic']
outputs = ['can']
- probes = [
+ tags = ['Automotive']
+ 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'],
- ]
-
- def __init__(self, **kwargs):
+ )
+ options = (
+ {'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 = (
+ ('data', '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'),
+ ('warning', 'Warning'),
+ ('bit', 'Bit'),
+ )
+ annotation_rows = (
+ ('bits', 'Bits', (15, 17)),
+ ('fields', 'Fields', tuple(range(15))),
+ ('warnings', 'Warnings', (16,)),
+ )
+
+ def __init__(self):
+ self.reset()
+
+ def reset(self):
+ 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')
+ def start(self):
+ self.out_ann = self.register(srd.OUTPUT_ANN)
+ self.out_python = self.register(srd.OUTPUT_PYTHON)
+
+ 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'])
- 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 set_fast_bitrate(self):
+ self.set_bit_rate(self.options['fast_bitrate'])
- 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['nominal_bitrate'])
+ self.sample_point = (self.bit_width / 100.0) * self.options['sample_point']
+ # Generic helper for CAN bit annotations.
+ def putg(self, ss, es, data):
+ left, right = int(self.sample_point), int(self.bit_width - self.sample_point)
+ self.put(ss - left, es + right, self.out_ann, data)
+
+ # Single-CAN-bit annotation using the current samplenum.
def putx(self, data):
- self.put(self.samplenum, self.samplenum, self.out_ann, data)
+ self.putg(self.samplenum, self.samplenum, data)
+
+ # Single-CAN-bit annotation using the samplenum of CAN bit 12.
+ 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)
+
+ def putpy(self, data):
+ self.put(self.ss_packet, self.es_packet, self.out_python, data)
def reset_variables(self):
self.state = 'IDLE'
self.bits = [] # Only actual CAN frame bits (no stuff bits)
self.curbit = 0 # Current bit of CAN frame (bit 0 == SOF)
self.last_databit = 999 # Positive value that bitnum+x will never match
-
- # Return True if we reached the desired bit position, False otherwise.
- def reached_bit(self, bitnum):
- bitpos = int(self.sof + (self.bit_width * bitnum) + self.bitpos)
- if self.samplenum >= bitpos:
- return True
- return False
+ self.ss_block = None
+ self.ss_bit12 = None
+ self.ss_bit32 = None
+ self.ss_databytebits = []
+ self.frame_bytes = []
+ self.rtr_type = None
+ 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
+ # aware of the SYNC phase's width nor the specific location of the edge,
+ # but improves the decoder's reliability when the input signal's bitrate
+ # does not exactly match the nominal rate.
+ def dom_edge_seen(self, force = False):
+ self.dom_edge_snum = self.samplenum
+ self.dom_edge_bcount = self.curbit
+
+ # Determine the position of the next desired bit's sample point.
+ def get_sample_point(self, bitnum):
+ samplenum = self.dom_edge_snum
+ samplenum += self.bit_width * (bitnum - self.dom_edge_bcount)
+ samplenum += self.sample_point
+ return int(samplenum)
def is_stuff_bit(self):
# CAN uses NRZ encoding and bit stuffing.
# After 5 identical bits, a stuff bit of opposite value is added.
+ # But not in the CRC delimiter, ACK, and end of frame fields.
+ if len(self.bits) > self.last_databit + 17:
+ return False
last_6_bits = self.rawbits[-6:]
if last_6_bits not in ([0, 0, 0, 0, 0, 1], [1, 1, 1, 1, 1, 0]):
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.bits.pop() # Drop last bit.
return True
# Returns True if the frame ended (EOF), False otherwise.
def decode_frame_end(self, can_rx, bitnum):
- # CRC sequence (15 bits)
- if bitnum == (self.last_databit + 15):
- 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.putx([0, ['CRC: 0x%04x' % self.crc]])
+ # 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"
+ x = self.last_databit + 1
+ crc_bits = self.bits[x:x + self.crc_len + 1]
+ self.crc = bitpack_msb(crc_bits)
+ 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.putx([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]])
+ 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([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]])
+ 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 + self.crc_len + 4):
+ self.ss_block = self.samplenum
# End of frame (EOF), 7 recessive bits
- elif bitnum == (self.last_databit + 25):
- self.putx([0, ['End of frame', 'EOF']])
+ 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']])
+ self.es_packet = self.samplenum
+ py_data = tuple([self.frame_type, self.fullid, self.rtr_type,
+ self.dlc, self.frame_bytes])
+ self.putpy(py_data)
self.reset_variables()
return True
# Returns True if the frame ended (EOF), False otherwise.
def decode_standard_frame(self, can_rx, bitnum):
- # Bit 14: RB0 (reserved bit)
- # Has to be sent dominant, but receivers should accept recessive too.
+ # 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.putx([0, ['RB0: %d' % can_rx]])
+ 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']])
+
+ if self.fd:
+ # 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
+ # Remote frames do not contain a data field.
+ rtr = 'remote' if self.bits[12] == 1 else 'data'
+ self.put12([8, ['Remote transmission request: %s frame' % rtr,
+ 'RTR: %s frame' % rtr, 'RTR']])
+ self.rtr_type = rtr
+ self.dlc_start = 15
+
+ 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']])
- # 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.putx([0, ['RTR: %s frame' % rtr]])
+ 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 == 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)
- self.putx([0, ['DLC: %d' % self.dlc]])
- self.last_databit = 18 + (self.dlc * 8)
+ elif bitnum == self.dlc_start + 3:
+ self.dlc = bitpack_msb(self.bits[self.dlc_start:self.dlc_start + 4])
+ self.putb([10, ['Data length code: %d' % self.dlc,
+ 'DLC: %d' % self.dlc, 'DLC']])
+ 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(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:
- for i in range(self.dlc):
- x = 18 + (8 * i) + 1
- b = int(''.join(str(d) for d in self.bits[x:x + 8]), 2)
- self.putx([0, ['Data byte %d: 0x%02x' % (i, b)]])
+ self.ss_databytebits.append(self.samplenum) # Last databyte bit.
+ for i in range(dlc2len(self.dlc)):
+ x = self.dlc_start + 4 + (8 * i)
+ b = bitpack_msb(self.bits[x:x + 8])
+ self.frame_bytes.append(b)
+ 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),
+ 'DB %d: 0x%02x' % (i, b), 'DB']])
+ self.ss_databytebits = []
elif bitnum > self.last_databit:
return self.decode_frame_end(can_rx, bitnum)
# Returns True if the frame ended (EOF), False otherwise.
def decode_extended_frame(self, can_rx, bitnum):
+ # 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])
- if bitnum == 31:
- self.eid = int(''.join(str(d) for d in self.bits[14:]), 2)
- self.putx([0, ['Extended ID: %d (0x%x)' % (self.eid, self.eid)]])
+ elif bitnum == 31:
+ self.eid = bitpack_msb(self.bits[14:])
+ 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.putx([0, ['Full ID: %d (0x%x)' % (self.fullid, self.fullid)]])
+ self.fullid = self.ident << 18 | self.eid
+ 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.putx([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.
+
+ # Remember start of RTR (see below).
if bitnum == 32:
- rtr = 'remote' if can_rx == 1 else 'data'
- self.putx([0, ['RTR: %s frame' % 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']])
+ self.rtr_type = rtr
# Bit 33: RB1 (reserved bit)
elif bitnum == 33:
- self.putx([0, ['RB1: %d' % can_rx]])
+ 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([0, ['RB0: %d' % can_rx]])
+ 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 == 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)
- self.putx([0, ['DLC: %d' % self.dlc]])
- self.last_databit = 38 + (self.dlc * 8)
+ elif bitnum == self.dlc_start + 3:
+ self.dlc = bitpack_msb(self.bits[self.dlc_start:self.dlc_start + 4])
+ self.putb([10, ['Data length code: %d' % self.dlc,
+ 'DLC: %d' % self.dlc, 'DLC']])
+ self.last_databit = self.dlc_start + 3 + (dlc2len(self.dlc) * 8)
+
+ # Remember all databyte bits, except the very last one.
+ 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:
- for i in range(self.dlc):
- x = 38 + (8 * i) + 1
- b = int(''.join(str(d) for d in self.bits[x:x + 8]), 2)
- self.putx([0, ['Data byte %d: 0x%02x' % (i, b)]])
+ self.ss_databytebits.append(self.samplenum) # Last databyte bit.
+ for i in range(dlc2len(self.dlc)):
+ x = self.dlc_start + 4 + (8 * i)
+ b = bitpack_msb(self.bits[x:x + 8])
+ self.frame_bytes.append(b)
+ 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),
+ 'DB %d: 0x%02x' % (i, b), 'DB']])
+ self.ss_databytebits = []
elif bitnum > self.last_databit:
return self.decode_frame_end(can_rx, bitnum)
# Get the index of the current CAN frame bit (without stuff bits).
bitnum = len(self.bits) - 1
- # For debugging.
- # self.putx([0, ['Bit %d (CAN bit %d): %d' % \
- # (self.curbit, bitnum, can_rx)]])
+ 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)]])
self.curbit += 1 # Increase self.curbit (bitnum is not affected).
return
+ else:
+ self.putx([17, [str(can_rx)]])
# Bit 0: Start of frame (SOF) bit
if bitnum == 0:
- if can_rx == 0:
- self.putx([0, ['Start of frame', 'SOF']])
- else:
- self.putx([1, ['Start of frame (SOF) must be a dominant bit']])
+ self.ss_packet = self.samplenum
+ self.putx([1, ['Start of frame', 'SOF', 'S']])
+ if can_rx != 0:
+ self.putx([16, ['Start of frame (SOF) must be a dominant bit']])
+
+ # Remember start of ID (see below).
+ elif bitnum == 1:
+ self.ss_block = self.samplenum
# Bits 1-11: Identifier (ID[10..0])
# 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.putx([0, ['ID: %d (0x%x)' % (self.id, self.id)]])
+ # BEWARE! Don't clobber the decoder's .id field which is
+ # part of its boiler plate!
+ self.ident = bitpack_msb(self.bits[1:])
+ self.fullid = self.ident
+ s = '%d (0x%x)' % (self.ident, self.ident),
+ self.putb([3, ['Identifier: %s' % s, 'ID: %s' % s, 'ID']])
+ if (self.ident & 0x7f0) == 0x7f0:
+ self.putb([16, ['Identifier bits 10..4 must not be all recessive']])
# RTR or SRR bit, depending on frame type (gets handled later).
elif bitnum == 12:
- # self.putx([0, ['RTR/SRR: %d' % can_rx]])
- pass
+ # self.putx([0, ['RTR/SRR: %d' % can_rx]]) # Debug only.
+ self.ss_bit12 = self.samplenum
# Bit 13: Identifier extension (IDE) bit
# 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):
- for (self.samplenum, pins) in data:
-
- (can_rx,) = pins
+ def decode(self):
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
+ while True:
# State machine.
if self.state == 'IDLE':
# Wait for a dominant state (logic 0) on the bus.
- if can_rx == 1:
- continue
+ (can_rx,) = self.wait({0: 'l'})
self.sof = self.samplenum
- # self.putx([0, ['SOF']])
+ self.dom_edge_seen(force = True)
self.state = 'GET BITS'
elif self.state == 'GET BITS':
# Wait until we're in the correct bit/sampling position.
- if not self.reached_bit(self.curbit):
- continue
- self.handle_bit(can_rx)
- else:
- raise Exception("Invalid state: %s" % self.state)
-
+ pos = self.get_sample_point(self.curbit)
+ (can_rx,) = self.wait([{'skip': pos - self.samplenum}, {0: 'f'}])
+ if self.matched[1]:
+ self.dom_edge_seen()
+ if self.matched[0]:
+ self.handle_bit(can_rx)
projects / libsigrokdecode.git / blobdiff