[libsigrokdecode.git] / decoders / sae_j1850_vpw / pd.py

##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2016 Anthony Symons <antus@pcmhacking.net>
##
## 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
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## 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, see <http://www.gnu.org/licenses/>.
##

import sigrokdecode as srd

class SamplerateError(Exception):
    pass

def timeuf(t):
    return int (t * 1000.0 * 1000.0)

def normalize_time(t):
    if t >= 1.0:
        return '%d s' % t
    elif t >= 0.001:
        return '%d ms' % (t * 1000.0)
    elif t >= 0.000001:
        return '%d μs' % (t * 1000.0 * 1000.0)
    elif t >= 0.000000001:
        return '%d ns' % (t * 1000.0 * 1000.0 * 1000.0)
    else:
        return '%f' % t

class Decoder(srd.Decoder):
    api_version = 3
    id = 'sae_j1850_vpw'
    name = 'SAE J1850 VPW'
    longname = 'SAE J1850 VPW.'
    desc = 'SAE J1850 Variable Pulse Width 1x and 4x.'
    license = 'gplv2+'
    inputs = ['logic']
    outputs = []
    tags = ['Automotive']
    channels = (
        {'id': 'data', 'name': 'Data', 'desc': 'Data line'},
    )
    annotations = (
        ('time', 'Time'),
        ('raw', 'Raw'),
        ('sof', 'SOF'),
        ('ifs', 'EOF/IFS'),
        ('data', 'Data'),
        ('packet', 'Packet'),
    )
    annotation_rows = (
        ('packets', 'Packets', (5,)),
        ('bytes', 'Bytes', (4,)),
        ('raws', 'Raws', (1,2,3,)),
        ('times', 'Times', (0,)),
    )

    def __init__(self):
        self.reset()

    def reset(self):
        self.state = 'IDLE'
        self.samplerate = None
        self.byte = 0      # the byte offset in the packet
        self.mode = 0      # for by packet decode
        self.data = 0      # the current byte
        self.datastart = 0 # sample number this byte started at
        self.csa = 0       # track the last byte seperately to retrospectively add the CS marker
        self.csb = 0
        self.count = 0     # which bit number we are up to
        self.active = 0    # which logic level is considered active

        # vpw timings. ideal, min and max tollerances.
        # From SAE J1850 1995 rev section 23.406

        self.sof = 200
        self.sofl = 164
        self.sofh = 245  # 240 by the spec, 245 so a 60us 4x sample will pass
        self.long = 128
        self.longl = 97
        self.longh = 170 # 164 by the spec but 170 for low sample rate tolerance.
        self.short = 64
        self.shortl = 24 # 35 by the spec, 24 to allow down to 6us as measured in practice for 4x @ 1mhz sampling
        self.shorth = 97
        self.ifs = 240
        self.spd = 1     # set to 4 when a 4x SOF is detected (VPW high speed frame)

    def handle_bit(self, ss, es, b):
        self.data |= (b << 7-self.count) # MSB-first
        self.put(ss, es, self.out_ann, [1, ["%d" % b]])
        if self.count == 0:
            self.datastart = ss
        if self.count == 7:
            self.csa = self.datastart # for CS
            self.csb = self.samplenum # for CS
            self.put(self.datastart, self.samplenum, self.out_ann, [4, ["%02X" % self.data]])
            # add protocol parsing here
            if self.byte == 0:
                self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Priority','Prio','P']])
            elif self.byte == 1:
                self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Destination','Dest','D']])
            elif self.byte == 2:
                self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Source','Src','S']])
            elif self.byte == 3:
                self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Mode','M']])
                self.mode = self.data
            elif self.mode == 1 and self.byte == 4: # mode 1 payload
                self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Pid','P']])

            # prepare for next byte
            self.count = -1
            self.data = 0
            self.byte = self.byte + 1 # track packet offset
        self.count = self.count + 1

    def metadata(self, key, value):
        if key == srd.SRD_CONF_SAMPLERATE:
            self.samplerate = value

    def start(self):
        self.out_ann = self.register(srd.OUTPUT_ANN)

    def decode(self):
        if not self.samplerate:
            raise SamplerateError('Cannot decode without samplerate.')

        self.wait({0: 'e'})
        es = self.samplenum
        while True:
            ss = es
            pin, = self.wait({0: 'e'})
            es = self.samplenum

            samples = es - ss
            txt = normalize_time(samples / self.samplerate)
            self.put(ss, es, self.out_ann, [0, [txt]])
            t = timeuf(samples / self.samplerate)
            if self.state == 'IDLE': # detect and set speed from the size of sof
                if pin == self.active and t in range(self.sofl , self.sofh):
                    self.put(ss, es, self.out_ann, [1, ['1X SOF', 'S1', 'S']])
                    self.spd = 1
                    self.data = 0
                    self.count = 0
                    self.state = 'DATA'
                elif pin == self.active and t in range(int(self.sofl / 4) , int(self.sofh / 4)):
                    self.put(ss, es, self.out_ann, [1, ['4X SOF', 'S4', '4']])
                    self.spd = 4
                    self.data = 0
                    self.count = 0
                    self.state = 'DATA'

            elif self.state == 'DATA':
                if t >= int(self.ifs / self.spd):
                    self.state = 'IDLE'
                    self.put(ss, es, self.out_ann, [1, ["EOF/IFS", "E"]]) # EOF=239-280 IFS=281+
                    self.put(self.csa, self.csb, self.out_ann, [5, ['Checksum','CS','C']]) # retrospective print of CS
                    self.byte = 0 # reset packet offset
                elif t in range(int(self.shortl / self.spd), int(self.shorth / self.spd)):
                    if pin == self.active:
                        self.handle_bit(ss, es, 1)
                    else:
                        self.handle_bit(ss, es, 0)
                elif t in range(int(self.longl / self.spd), int(self.longh / self.spd)):
                    if pin == self.active:
                        self.handle_bit(ss, es, 0)
                    else:
                        self.handle_bit(ss, es, 1)
Commit	Line	Data
3bd25dea AS	1	##
	2	## This file is part of the libsigrokdecode project.
	3	##
	4	## Copyright (C) 2016 Anthony Symons <antus@pcmhacking.net>
	5	##
	6	## This program is free software; you can redistribute it and/or modify
	7	## it under the terms of the GNU General Public License as published by
	8	## the Free Software Foundation; either version 2 of the License, or
	9	## (at your option) any later version.
	10	##
	11	## This program is distributed in the hope that it will be useful,
	12	## but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	## GNU General Public License for more details.
	15	##
	16	## You should have received a copy of the GNU General Public License
41e0dd7a	17	## along with this program; if not, see <http://www.gnu.org/licenses/>.
3bd25dea AS	18	##
	19
	20	import sigrokdecode as srd
	21
	22	class SamplerateError(Exception):
	23	pass
	24
	25	def timeuf(t):
	26	return int (t * 1000.0 * 1000.0)
	27
	28	def normalize_time(t):
	29	if t >= 1.0:
	30	return '%d s' % t
	31	elif t >= 0.001:
	32	return '%d ms' % (t * 1000.0)
	33	elif t >= 0.000001:
	34	return '%d μs' % (t * 1000.0 * 1000.0)
	35	elif t >= 0.000000001:
	36	return '%d ns' % (t * 1000.0 * 1000.0 * 1000.0)
	37	else:
	38	return '%f' % t
	39
	40	class Decoder(srd.Decoder):
41e0dd7a GS	41	api_version = 3
	42	id = 'sae_j1850_vpw'
	43	name = 'SAE J1850 VPW'
	44	longname = 'SAE J1850 VPW.'
	45	desc = 'SAE J1850 Variable Pulse Width 1x and 4x.'
3bd25dea AS	46	license = 'gplv2+'
3bd25dea AS	47	inputs = ['logic']
41e0dd7a GS	48	outputs = []
41e0dd7a GS	49	tags = ['Automotive']
3bd25dea AS	50	channels = (
	51	{'id': 'data', 'name': 'Data', 'desc': 'Data line'},
	52	)
	53	annotations = (
	54	('time', 'Time'),
	55	('raw', 'Raw'),
	56	('sof', 'SOF'),
	57	('ifs', 'EOF/IFS'),
	58	('data', 'Data'),
	59	('packet', 'Packet'),
	60	)
	61	annotation_rows = (
41e0dd7a GS	62	('packets', 'Packets', (5,)),
	63	('bytes', 'Bytes', (4,)),
	64	('raws', 'Raws', (1,2,3,)),
	65	('times', 'Times', (0,)),
3bd25dea AS	66	)
3bd25dea AS	67
41e0dd7a GS	68	def __init__(self):
	69	self.reset()
	70
	71	def reset(self):
3bd25dea AS	72	self.state = 'IDLE'
3bd25dea AS	73	self.samplerate = None
3bd25dea AS	74	self.byte = 0 # the byte offset in the packet
	75	self.mode = 0 # for by packet decode
	76	self.data = 0 # the current byte
	77	self.datastart = 0 # sample number this byte started at
	78	self.csa = 0 # track the last byte seperately to retrospectively add the CS marker
	79	self.csb = 0
41e0dd7a	80	self.count = 0 # which bit number we are up to
3bd25dea	81	self.active = 0 # which logic level is considered active
41e0dd7a GS	82
41e0dd7a GS	83	# vpw timings. ideal, min and max tollerances.
3bd25dea	84	# From SAE J1850 1995 rev section 23.406
41e0dd7a	85
3bd25dea AS	86	self.sof = 200
	87	self.sofl = 164
	88	self.sofh = 245 # 240 by the spec, 245 so a 60us 4x sample will pass
	89	self.long = 128
	90	self.longl = 97
	91	self.longh = 170 # 164 by the spec but 170 for low sample rate tolerance.
	92	self.short = 64
	93	self.shortl = 24 # 35 by the spec, 24 to allow down to 6us as measured in practice for 4x @ 1mhz sampling
	94	self.shorth = 97
	95	self.ifs = 240
	96	self.spd = 1 # set to 4 when a 4x SOF is detected (VPW high speed frame)
41e0dd7a GS	97
41e0dd7a GS	98	def handle_bit(self, ss, es, b):
3bd25dea	99	self.data \|= (b << 7-self.count) # MSB-first
41e0dd7a	100	self.put(ss, es, self.out_ann, [1, ["%d" % b]])
3bd25dea	101	if self.count == 0:
41e0dd7a	102	self.datastart = ss
3bd25dea AS	103	if self.count == 7:
	104	self.csa = self.datastart # for CS
	105	self.csb = self.samplenum # for CS
	106	self.put(self.datastart, self.samplenum, self.out_ann, [4, ["%02X" % self.data]])
	107	# add protocol parsing here
	108	if self.byte == 0:
	109	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Priority','Prio','P']])
	110	elif self.byte == 1:
	111	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Destination','Dest','D']])
	112	elif self.byte == 2:
	113	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Source','Src','S']])
	114	elif self.byte == 3:
	115	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Mode','M']])
41e0dd7a	116	self.mode = self.data
3bd25dea AS	117	elif self.mode == 1 and self.byte == 4: # mode 1 payload
3bd25dea AS	118	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Pid','P']])
41e0dd7a	119
3bd25dea AS	120	# prepare for next byte
	121	self.count = -1
	122	self.data = 0
	123	self.byte = self.byte + 1 # track packet offset
	124	self.count = self.count + 1
41e0dd7a	125
3bd25dea AS	126	def metadata(self, key, value):
	127	if key == srd.SRD_CONF_SAMPLERATE:
	128	self.samplerate = value
	129
	130	def start(self):
	131	self.out_ann = self.register(srd.OUTPUT_ANN)
	132
41e0dd7a	133	def decode(self):
3bd25dea AS	134	if not self.samplerate:
	135	raise SamplerateError('Cannot decode without samplerate.')
	136
41e0dd7a GS	137	self.wait({0: 'e'})
	138	es = self.samplenum
	139	while True:
	140	ss = es
	141	pin, = self.wait({0: 'e'})
	142	es = self.samplenum
	143
	144	samples = es - ss
	145	txt = normalize_time(samples / self.samplerate)
	146	self.put(ss, es, self.out_ann, [0, [txt]])
	147	t = timeuf(samples / self.samplerate)
	148	if self.state == 'IDLE': # detect and set speed from the size of sof
	149	if pin == self.active and t in range(self.sofl , self.sofh):
	150	self.put(ss, es, self.out_ann, [1, ['1X SOF', 'S1', 'S']])
	151	self.spd = 1
	152	self.data = 0
	153	self.count = 0
	154	self.state = 'DATA'
	155	elif pin == self.active and t in range(int(self.sofl / 4) , int(self.sofh / 4)):
	156	self.put(ss, es, self.out_ann, [1, ['4X SOF', 'S4', '4']])
	157	self.spd = 4
	158	self.data = 0
	159	self.count = 0
	160	self.state = 'DATA'
	161
	162	elif self.state == 'DATA':
	163	if t >= int(self.ifs / self.spd):
	164	self.state = 'IDLE'
	165	self.put(ss, es, self.out_ann, [1, ["EOF/IFS", "E"]]) # EOF=239-280 IFS=281+
	166	self.put(self.csa, self.csb, self.out_ann, [5, ['Checksum','CS','C']]) # retrospective print of CS
	167	self.byte = 0 # reset packet offset
	168	elif t in range(int(self.shortl / self.spd), int(self.shorth / self.spd)):
	169	if pin == self.active:
	170	self.handle_bit(ss, es, 1)
	171	else:
	172	self.handle_bit(ss, es, 0)
	173	elif t in range(int(self.longl / self.spd), int(self.longh / self.spd)):
	174	if pin == self.active:
	175	self.handle_bit(ss, es, 0)
	176	else:
	177	self.handle_bit(ss, es, 1)