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03325c23 GM |
1 | ## |
2 | ## This file is part of the sigrok project. | |
3 | ## | |
4 | ## Copyright (C) 2011 Gareth McMullin <gareth@blacksphere.co.nz> | |
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 | ||
156509ca | 21 | # USB (full-speed) protocol decoder |
03325c23 | 22 | |
677d597b | 23 | import sigrokdecode as srd |
03325c23 | 24 | |
2b716038 | 25 | # Symbols (used as states of our state machine, too) |
03325c23 | 26 | syms = { |
2b716038 UH |
27 | (0, 0): 'SE0', |
28 | (1, 0): 'J', | |
29 | (0, 1): 'K', | |
30 | (1, 1): 'SE1', | |
03325c23 GM |
31 | } |
32 | ||
bbe99ad5 UH |
33 | # ... |
34 | pids = { | |
35 | '10000111': 'OUT', # Tokens | |
36 | '10010110': 'IN', | |
37 | '10100101': 'SOF', | |
38 | '10110100': 'SETUP', | |
39 | '11000011': 'DATA0', # Data | |
40 | '11010010': 'DATA1', | |
41 | '01001011': 'ACK', # Handshake | |
42 | '01011010': 'NAK', | |
43 | '01111000': 'STALL', | |
44 | '01101001': 'NYET', | |
45 | } | |
46 | ||
03325c23 | 47 | def bitstr_to_num(bitstr): |
eb7082c9 UH |
48 | if not bitstr: |
49 | return 0 | |
03325c23 GM |
50 | l = list(bitstr) |
51 | l.reverse() | |
52 | return int(''.join(l), 2) | |
53 | ||
54 | def packet_decode(packet): | |
03325c23 GM |
55 | sync = packet[:8] |
56 | pid = packet[8:16] | |
57 | pid = pids.get(pid, pid) | |
eb7082c9 | 58 | |
9611dc5f | 59 | # Remove CRC. |
03325c23 GM |
60 | if pid in ('OUT', 'IN', 'SOF', 'SETUP'): |
61 | data = packet[16:-5] | |
62 | if pid == 'SOF': | |
63 | data = str(bitstr_to_num(data)) | |
64 | else: | |
65 | dev = bitstr_to_num(data[:7]) | |
66 | ep = bitstr_to_num(data[7:]) | |
eb7082c9 | 67 | data = 'DEV %d EP %d' % (dev, ep) |
03325c23 GM |
68 | |
69 | elif pid in ('DATA0', 'DATA1'): | |
70 | data = packet[16:-16] | |
eb7082c9 | 71 | tmp = '' |
03325c23 | 72 | while data: |
0690a587 | 73 | tmp += '%02x ' % bitstr_to_num(data[:8]) |
03325c23 GM |
74 | data = data[8:] |
75 | data = tmp | |
76 | else: | |
77 | data = packet[16:] | |
78 | ||
eb7082c9 UH |
79 | if sync != '00000001': |
80 | return 'SYNC INVALID!' | |
9611dc5f | 81 | |
03325c23 GM |
82 | return pid + ' ' + data |
83 | ||
677d597b | 84 | class Decoder(srd.Decoder): |
a2c2afd9 | 85 | api_version = 1 |
67e847fd | 86 | id = 'usb' |
03325c23 | 87 | name = 'USB' |
0690a587 | 88 | longname = 'Universal Serial Bus' |
9a12a6e7 | 89 | desc = 'Universal Serial Bus' |
03325c23 | 90 | longdesc = '...longdesc...' |
03325c23 GM |
91 | license = 'gplv2+' |
92 | inputs = ['logic'] | |
93 | outputs = ['usb'] | |
ea42f53e UH |
94 | probes = [ |
95 | {'id': 'dp', 'name': 'D+', 'desc': 'USB D+ signal'}, | |
96 | {'id': 'dm', 'name': 'D-', 'desc': 'USB D- signal'}, | |
97 | ] | |
b77614bc | 98 | optional_probes = [] |
03325c23 | 99 | options = {} |
0690a587 UH |
100 | annotations = [ |
101 | ['TODO', 'TODO'] | |
102 | ] | |
03325c23 GM |
103 | |
104 | def __init__(self): | |
d0e93c76 | 105 | pass |
03325c23 GM |
106 | |
107 | def start(self, metadata): | |
03325c23 | 108 | self.rate = metadata['samplerate'] |
0690a587 | 109 | |
56202222 UH |
110 | # self.out_proto = self.add(srd.OUTPUT_PROTO, 'usb') |
111 | self.out_ann = self.add(srd.OUTPUT_ANN, 'usb') | |
0690a587 | 112 | |
03325c23 | 113 | if self.rate < 48000000: |
decde15e UH |
114 | raise Exception('Sample rate (%d) not sufficient for USB ' |
115 | 'decoding, need at least 48MHz' % self.rate) | |
0690a587 | 116 | |
9611dc5f | 117 | # Initialise decoder state. |
2b716038 | 118 | self.sym = 'J' |
03325c23 GM |
119 | self.scount = 0 |
120 | self.packet = '' | |
121 | ||
decde15e UH |
122 | def report(self): |
123 | pass | |
b327337f | 124 | |
decde15e | 125 | def decode(self, ss, es, data): |
0690a587 | 126 | for (samplenum, (dm, dp)) in data: |
03325c23 GM |
127 | |
128 | self.scount += 1 | |
129 | ||
ea42f53e | 130 | sym = syms[dp, dm] |
0690a587 UH |
131 | |
132 | # ... | |
03325c23 GM |
133 | if sym == self.sym: |
134 | continue | |
135 | ||
136 | if self.scount == 1: | |
9611dc5f UH |
137 | # We ignore single sample width pulses. |
138 | # I sometimes get these with the OLS. | |
03325c23 GM |
139 | self.sym = sym |
140 | self.scount = 0 | |
141 | continue | |
142 | ||
9611dc5f | 143 | # How many bits since the last transition? |
2b716038 | 144 | if self.packet != '' or self.sym != 'J': |
b327337f | 145 | bitcount = int((self.scount - 1) * 12000000 / self.rate) |
03325c23 GM |
146 | else: |
147 | bitcount = 0 | |
148 | ||
2b716038 | 149 | if self.sym == 'SE0': |
03325c23 | 150 | if bitcount == 1: |
9611dc5f | 151 | # End-Of-Packet (EOP) |
0690a587 UH |
152 | self.put(0, 0, self.out_ann, |
153 | [0, [packet_decode(self.packet), self.packet]]) | |
03325c23 | 154 | else: |
9611dc5f | 155 | # Longer than EOP, assume reset. |
0690a587 | 156 | self.put(0, 0, self.out_ann, [0, ['RESET']]) |
03325c23 GM |
157 | self.scount = 0 |
158 | self.sym = sym | |
159 | self.packet = '' | |
160 | continue | |
161 | ||
162 | # Add bits to the packet string. | |
163 | self.packet += '1' * bitcount | |
0690a587 | 164 | |
9611dc5f | 165 | # Handle bit stuffing. |
2b716038 | 166 | if bitcount < 6 and sym != 'SE0': |
03325c23 GM |
167 | self.packet += '0' |
168 | elif bitcount > 6: | |
0690a587 | 169 | self.put(0, 0, self.out_ann, [0, ['BIT STUFF ERROR']]) |
9611dc5f | 170 | |
03325c23 GM |
171 | self.scount = 0 |
172 | self.sym = sym | |
173 |