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9cfb16e8 IJ |
1 | ## |
2 | ## This file is part of the sigrok project. | |
3 | ## | |
4 | ## Copyright (C) 2012 Iztok Jeras <iztok.jeras@gmail.com> | |
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 | ||
6188e4e4 | 21 | # 1-Wire protocol decoder (network layer) |
9cfb16e8 IJ |
22 | |
23 | import sigrokdecode as srd | |
24 | ||
6188e4e4 | 25 | # Dictionary of ROM commands and their names, next state. |
758d2ea9 | 26 | command = { |
6188e4e4 UH |
27 | 0x33: ['READ ROM' , 'GET ROM' ], |
28 | 0x0f: ['CONDITIONAL READ ROM' , 'GET ROM' ], | |
29 | 0xcc: ['SKIP ROM' , 'TRANSPORT' ], | |
30 | 0x55: ['MATCH ROM' , 'GET ROM' ], | |
31 | 0xf0: ['SEARCH ROM' , 'SEARCH ROM'], | |
32 | 0xec: ['CONDITIONAL SEARCH ROM', 'SEARCH ROM'], | |
33 | 0x3c: ['OVERDRIVE SKIP ROM' , 'TRANSPORT' ], | |
34 | 0x6d: ['OVERDRIVE MATCH ROM' , 'GET ROM' ], | |
758d2ea9 | 35 | } |
9cfb16e8 IJ |
36 | |
37 | class Decoder(srd.Decoder): | |
38 | api_version = 1 | |
39 | id = 'onewire_network' | |
40 | name = '1-Wire network layer' | |
6188e4e4 | 41 | longname = '1-Wire serial communication bus (network layer)' |
9cfb16e8 IJ |
42 | desc = 'Bidirectional, half-duplex, asynchronous serial bus.' |
43 | license = 'gplv2+' | |
44 | inputs = ['onewire_link'] | |
45 | outputs = ['onewire_network'] | |
46 | probes = [] | |
47 | optional_probes = [] | |
48 | options = {} | |
49 | annotations = [ | |
50 | ['Network', 'Network layer events (device addressing)'], | |
9cfb16e8 IJ |
51 | ] |
52 | ||
53 | def __init__(self, **kwargs): | |
54 | # Event timing variables | |
48b59746 UH |
55 | self.beg = 0 |
56 | self.end = 0 | |
9cfb16e8 | 57 | # Network layer variables |
6188e4e4 | 58 | self.state = 'COMMAND' |
9cfb16e8 | 59 | self.bit_cnt = 0 |
6188e4e4 UH |
60 | self.search = 'P' |
61 | self.data_p = 0x0 | |
62 | self.data_n = 0x0 | |
63 | self.data = 0x0 | |
48b59746 | 64 | self.rom = 0x0000000000000000 |
9cfb16e8 IJ |
65 | |
66 | def start(self, metadata): | |
67 | self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_network') | |
6188e4e4 | 68 | self.out_ann = self.add(srd.OUTPUT_ANN, 'onewire_network') |
9cfb16e8 IJ |
69 | |
70 | def report(self): | |
71 | pass | |
72 | ||
6188e4e4 UH |
73 | def putx(self, data): |
74 | # Helper function for most annotations. | |
48b59746 | 75 | self.put(self.beg, self.end, self.out_ann, data) |
6188e4e4 UH |
76 | |
77 | def puty(self, data): | |
78 | # Helper function for most protocol packets. | |
48b59746 | 79 | self.put(self.beg, self.end, self.out_proto, data) |
6188e4e4 | 80 | |
9cfb16e8 | 81 | def decode(self, ss, es, data): |
6188e4e4 | 82 | code, val = data |
9cfb16e8 IJ |
83 | |
84 | # State machine. | |
6188e4e4 UH |
85 | if code == 'RESET/PRESENCE': |
86 | self.search = 'P' | |
9cfb16e8 | 87 | self.bit_cnt = 0 |
6188e4e4 UH |
88 | self.put(ss, es, self.out_ann, |
89 | [0, ['RESET/PRESENCE: %s' % ('True' if val else 'False')]]) | |
a81787f6 | 90 | self.put(ss, es, self.out_proto, ['RESET/PRESENCE', val]) |
6188e4e4 | 91 | self.state = 'COMMAND' |
48b59746 UH |
92 | return |
93 | ||
94 | # For now we're only interested in 'RESET/PRESENCE' and 'BIT' packets. | |
95 | if code != 'BIT': | |
96 | return | |
97 | ||
98 | if self.state == 'COMMAND': | |
99 | # Receiving and decoding a ROM command. | |
100 | if self.onewire_collect(8, val, ss, es) == 0: | |
101 | return | |
102 | if self.data in command: | |
103 | self.putx([0, ['ROM COMMAND: 0x%02x \'%s\'' | |
104 | % (self.data, command[self.data][0])]]) | |
105 | self.state = command[self.data][1] | |
9cfb16e8 | 106 | else: |
48b59746 UH |
107 | self.putx([0, ['ROM COMMAND: 0x%02x \'%s\'' |
108 | % (self.data, 'UNRECOGNIZED')]]) | |
109 | self.state = 'COMMAND ERROR' | |
110 | elif self.state == 'GET ROM': | |
111 | # A 64 bit device address is selected. | |
112 | # Family code (1B) + serial number (6B) + CRC (1B) | |
113 | if self.onewire_collect(64, val, ss, es) == 0: | |
114 | return | |
115 | self.rom = self.data & 0xffffffffffffffff | |
116 | self.putx([0, ['ROM: 0x%016x' % self.rom]]) | |
117 | self.puty(['ROM', self.rom]) | |
118 | self.state = 'TRANSPORT' | |
119 | elif self.state == 'SEARCH ROM': | |
120 | # A 64 bit device address is searched for. | |
121 | # Family code (1B) + serial number (6B) + CRC (1B) | |
122 | if self.onewire_search(64, val, ss, es) == 0: | |
123 | return | |
124 | self.rom = self.data & 0xffffffffffffffff | |
125 | self.putx([0, ['ROM: 0x%016x' % self.rom]]) | |
126 | self.puty(['ROM', self.rom]) | |
127 | self.state = 'TRANSPORT' | |
128 | elif self.state == 'TRANSPORT': | |
129 | # The transport layer is handled in byte sized units. | |
130 | if self.onewire_collect(8, val, ss, es) == 0: | |
131 | return | |
132 | self.putx([0, ['DATA: 0x%02x' % self.data]]) | |
133 | self.puty(['DATA', self.data]) | |
134 | elif self.state == 'COMMAND ERROR': | |
135 | # Since the command is not recognized, print raw data. | |
136 | if self.onewire_collect(8, val, ss, es) == 0: | |
137 | return | |
138 | self.putx([0, ['ROM ERROR DATA: 0x%02x' % self.data]]) | |
139 | else: | |
140 | raise Exception('Invalid state: %s' % self.state) | |
9cfb16e8 | 141 | |
48b59746 | 142 | # Data collector. |
6188e4e4 UH |
143 | def onewire_collect(self, length, val, ss, es): |
144 | # Storing the sample this sequence begins with. | |
145 | if self.bit_cnt == 1: | |
48b59746 | 146 | self.beg = ss |
9cfb16e8 | 147 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) |
6188e4e4 UH |
148 | self.bit_cnt += 1 |
149 | # Storing the sample this sequence ends with. | |
150 | # In case the full length of the sequence is received, return 1. | |
151 | if self.bit_cnt == length: | |
48b59746 | 152 | self.end = es |
6188e4e4 UH |
153 | self.data = self.data & ((1 << length) - 1) |
154 | self.bit_cnt = 0 | |
155 | return 1 | |
9cfb16e8 | 156 | else: |
6188e4e4 | 157 | return 0 |
9cfb16e8 | 158 | |
48b59746 | 159 | # Search collector. |
6188e4e4 UH |
160 | def onewire_search(self, length, val, ss, es): |
161 | # Storing the sample this sequence begins with. | |
162 | if (self.bit_cnt == 0) and (self.search == 'P'): | |
48b59746 | 163 | self.beg = ss |
6188e4e4 UH |
164 | |
165 | if self.search == 'P': | |
166 | # Master receives an original address bit. | |
167 | self.data_p = self.data_p & ~(1 << self.bit_cnt) | \ | |
168 | (val << self.bit_cnt) | |
169 | self.search = 'N' | |
170 | elif self.search == 'N': | |
171 | # Master receives a complemented address bit. | |
172 | self.data_n = self.data_n & ~(1 << self.bit_cnt) | \ | |
173 | (val << self.bit_cnt) | |
174 | self.search = 'D' | |
175 | elif self.search == 'D': | |
176 | # Master transmits an address bit. | |
177 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
178 | self.search = 'P' | |
179 | self.bit_cnt += 1 | |
180 | ||
181 | # Storing the sample this sequence ends with. | |
182 | # In case the full length of the sequence is received, return 1. | |
183 | if self.bit_cnt == length: | |
48b59746 | 184 | self.end = es |
6188e4e4 UH |
185 | self.data_p = self.data_p & ((1 << length) - 1) |
186 | self.data_n = self.data_n & ((1 << length) - 1) | |
187 | self.data = self.data & ((1 << length) - 1) | |
188 | self.search = 'P' | |
189 | self.bit_cnt = 0 | |
190 | return 1 | |
9cfb16e8 | 191 | else: |
6188e4e4 | 192 | return 0 |