## 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 = [
- ['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'],
- ]
+ )
+ 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):
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)
-