[libsigrokdecode.git] / decoders / 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, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
##

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 = 2
    id = 'vpw'
    name = 'VPW'
    longname = 'J1850 VPW Decoder'
    desc = 'Decode J1850 VPW 1x and 4x'
    license = 'gplv2+'
    inputs = ['logic']
    outputs = ['timing']
    channels = (
        {'id': 'data', 'name': 'Data', 'desc': 'Data line'},
    )
    annotations = (
        ('time', 'Time'),
        ('raw', 'Raw'),
        ('sof', 'SOF'),
        ('ifs', 'EOF/IFS'),
        ('data', 'Data'),
        ('packet', 'Packet'),
    )
    annotation_rows = (
        ('packet', 'Packet', (5,)),
        ('byte', 'Byte', (4,)),
        ('raw', 'Raw', (1,2,3,)),
        ('time', 'Time', (0,)),
    )

    def __init__(self, **kwargs):
        self.state = 'IDLE'
        self.samplerate = None
        self.oldpin = None
        self.last_samplenum = 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, b):
        self.data |= (b << 7-self.count) # MSB-first
        self.put(self.last_samplenum, self.samplenum, self.out_ann, [1, ["%d" % b]])
        if self.count == 0:
            self.datastart = self.last_samplenum
        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, ss, es, data):
        if not self.samplerate:
            raise SamplerateError('Cannot decode without samplerate.')

        for (self.samplenum, (pin,)) in data:
            # Ignore identical samples early on (for performance reasons).
            if self.oldpin == pin:
                continue

            if self.oldpin is None:
                self.oldpin = pin
                self.last_samplenum = self.samplenum
                continue

            if self.oldpin != pin:
                samples = self.samplenum - self.last_samplenum
                txt=normalize_time(samples / self.samplerate)
                self.put(self.last_samplenum, self.samplenum, 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(self.last_samplenum, self.samplenum, 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(self.last_samplenum, self.samplenum, 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(self.last_samplenum, self.samplenum, 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(1)
                        else:
                            self.handle_bit(0)
                    elif t in range(int(self.longl/self.spd), int(self.longh/self.spd)):
                        if pin==self.active:
                            self.handle_bit(0)
                        else:
                            self.handle_bit(1)

                # Store data for next round.
                self.last_samplenum = self.samplenum
                self.oldpin = pin
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
	17	## along with this program; if not, write to the Free Software
	18	## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	##
	20
	21	import sigrokdecode as srd
	22
	23	class SamplerateError(Exception):
	24	pass
	25
	26	def timeuf(t):
	27	return int (t * 1000.0 * 1000.0)
	28
	29	def normalize_time(t):
	30	if t >= 1.0:
	31	return '%d s' % t
	32	elif t >= 0.001:
	33	return '%d ms' % (t * 1000.0)
	34	elif t >= 0.000001:
	35	return '%d μs' % (t * 1000.0 * 1000.0)
	36	elif t >= 0.000000001:
	37	return '%d ns' % (t * 1000.0 * 1000.0 * 1000.0)
	38	else:
	39	return '%f' % t
	40
	41	class Decoder(srd.Decoder):
	42	api_version = 2
	43	id = 'vpw'
	44	name = 'VPW'
	45	longname = 'J1850 VPW Decoder'
	46	desc = 'Decode J1850 VPW 1x and 4x'
	47	license = 'gplv2+'
	48	inputs = ['logic']
	49	outputs = ['timing']
	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 = (
	62	('packet', 'Packet', (5,)),
	63	('byte', 'Byte', (4,)),
	64	('raw', 'Raw', (1,2,3,)),
65	('time', 'Time', (0,)),
66	)
67
68	def __init__(self, **kwargs):
69	self.state = 'IDLE'
70	self.samplerate = None
71	self.oldpin = None
72	self.last_samplenum = None
73	self.byte = 0 # the byte offset in the packet
74	self.mode = 0 # for by packet decode
75	self.data = 0 # the current byte
76	self.datastart = 0 # sample number this byte started at
77	self.csa = 0 # track the last byte seperately to retrospectively add the CS marker
78	self.csb = 0
79	self.count = 0 # which bit number we are up to
80	self.active = 0 # which logic level is considered active
81
82	# vpw timings. ideal, min and max tollerances.
83	# From SAE J1850 1995 rev section 23.406
84
85	self.sof = 200
86	self.sofl = 164
87	self.sofh = 245 # 240 by the spec, 245 so a 60us 4x sample will pass
88	self.long = 128
89	self.longl = 97
90	self.longh = 170 # 164 by the spec but 170 for low sample rate tolerance.
91	self.short = 64
92	self.shortl = 24 # 35 by the spec, 24 to allow down to 6us as measured in practice for 4x @ 1mhz sampling
93	self.shorth = 97
94	self.ifs = 240
95	self.spd = 1 # set to 4 when a 4x SOF is detected (VPW high speed frame)
96
97	def handle_bit(self, b):
98	self.data \|= (b << 7-self.count) # MSB-first
99	self.put(self.last_samplenum, self.samplenum, self.out_ann, [1, ["%d" % b]])
100	if self.count == 0:
101	self.datastart = self.last_samplenum
102	if self.count == 7:
103	self.csa = self.datastart # for CS
104	self.csb = self.samplenum # for CS
105	self.put(self.datastart, self.samplenum, self.out_ann, [4, ["%02X" % self.data]])
106	# add protocol parsing here
107	if self.byte == 0:
108	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Priority','Prio','P']])
109	elif self.byte == 1:
110	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Destination','Dest','D']])
111	elif self.byte == 2:
112	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Source','Src','S']])
113	elif self.byte == 3:
114	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Mode','M']])
115	self.mode=self.data
116	elif self.mode == 1 and self.byte == 4: # mode 1 payload
117	self.put(self.datastart, self.samplenum, self.out_ann, [5, ['Pid','P']])
118
119	# prepare for next byte
120	self.count = -1
121	self.data = 0
122	self.byte = self.byte + 1 # track packet offset
123	self.count = self.count + 1
124
125	def metadata(self, key, value):
126	if key == srd.SRD_CONF_SAMPLERATE:
127	self.samplerate = value
128
129	def start(self):
130	self.out_ann = self.register(srd.OUTPUT_ANN)
131
132	def decode(self, ss, es, data):
133	if not self.samplerate:
134	raise SamplerateError('Cannot decode without samplerate.')
135
136	for (self.samplenum, (pin,)) in data:
137	# Ignore identical samples early on (for performance reasons).
138	if self.oldpin == pin:
139	continue
140
141	if self.oldpin is None:
142	self.oldpin = pin
143	self.last_samplenum = self.samplenum
144	continue
145
146	if self.oldpin != pin:
147	samples = self.samplenum - self.last_samplenum
148	txt=normalize_time(samples / self.samplerate)
149	self.put(self.last_samplenum, self.samplenum, self.out_ann, [0, [txt]])
150	t=timeuf(samples / self.samplerate)
151	if self.state == 'IDLE': # detect and set speed from the size of sof
152	if pin==self.active and t in range(self.sofl , self.sofh):
153	self.put(self.last_samplenum, self.samplenum, self.out_ann, [1, ['1X SOF', 'S1', 'S']])
154	self.spd = 1
155	self.data = 0
156	self.count = 0
157	self.state = 'DATA'
158	elif pin==self.active and t in range(int(self.sofl/4) , int(self.sofh/4)):
159	self.put(self.last_samplenum, self.samplenum, self.out_ann, [1, ['4X SOF', 'S4', '4']])
160	self.spd = 4
161	self.data = 0
162	self.count = 0
163	self.state = 'DATA'
164
165	elif self.state == 'DATA':
166	if t >= int(self.ifs/self.spd):
167	self.state = 'IDLE'
168	self.put(self.last_samplenum, self.samplenum, self.out_ann, [1, ["EOF/IFS", "E"]]) # EOF=239-280 IFS=281+
169	self.put(self.csa, self.csb, self.out_ann, [5, ['Checksum','CS','C']]) # retrospective print of CS
170	self.byte = 0 # reset packet offset
171	elif t in range(int(self.shortl/self.spd), int(self.shorth/self.spd)):
172	if pin==self.active:
173	self.handle_bit(1)
174	else:
175	self.handle_bit(0)
176	elif t in range(int(self.longl/self.spd), int(self.longh/self.spd)):
177	if pin==self.active:
178	self.handle_bit(0)
179	else:
180	self.handle_bit(1)
181
182	# Store data for next round.
183	self.last_samplenum = self.samplenum
184	self.oldpin = pin