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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 = { |
1fe967f2 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 | 0x69: ['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 = [ | |
3f302d51 | 50 | ['Text', 'Human-readable text'], |
9cfb16e8 IJ |
51 | ] |
52 | ||
53 | def __init__(self, **kwargs): | |
48b59746 UH |
54 | self.beg = 0 |
55 | self.end = 0 | |
6188e4e4 | 56 | self.state = 'COMMAND' |
9cfb16e8 | 57 | self.bit_cnt = 0 |
6188e4e4 UH |
58 | self.search = 'P' |
59 | self.data_p = 0x0 | |
60 | self.data_n = 0x0 | |
61 | self.data = 0x0 | |
48b59746 | 62 | self.rom = 0x0000000000000000 |
9cfb16e8 IJ |
63 | |
64 | def start(self, metadata): | |
65 | self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_network') | |
6188e4e4 | 66 | self.out_ann = self.add(srd.OUTPUT_ANN, 'onewire_network') |
9cfb16e8 IJ |
67 | |
68 | def report(self): | |
69 | pass | |
70 | ||
6188e4e4 UH |
71 | def putx(self, data): |
72 | # Helper function for most annotations. | |
48b59746 | 73 | self.put(self.beg, self.end, self.out_ann, data) |
6188e4e4 UH |
74 | |
75 | def puty(self, data): | |
76 | # Helper function for most protocol packets. | |
48b59746 | 77 | self.put(self.beg, self.end, self.out_proto, data) |
6188e4e4 | 78 | |
9cfb16e8 | 79 | def decode(self, ss, es, data): |
6188e4e4 | 80 | code, val = data |
9cfb16e8 IJ |
81 | |
82 | # State machine. | |
6188e4e4 UH |
83 | if code == 'RESET/PRESENCE': |
84 | self.search = 'P' | |
9cfb16e8 | 85 | self.bit_cnt = 0 |
6188e4e4 | 86 | self.put(ss, es, self.out_ann, |
3f302d51 | 87 | [0, ['Reset/presence: %s' % ('true' if val else 'false')]]) |
a81787f6 | 88 | self.put(ss, es, self.out_proto, ['RESET/PRESENCE', val]) |
6188e4e4 | 89 | self.state = 'COMMAND' |
48b59746 UH |
90 | return |
91 | ||
92 | # For now we're only interested in 'RESET/PRESENCE' and 'BIT' packets. | |
93 | if code != 'BIT': | |
94 | return | |
95 | ||
96 | if self.state == 'COMMAND': | |
97 | # Receiving and decoding a ROM command. | |
98 | if self.onewire_collect(8, val, ss, es) == 0: | |
99 | return | |
100 | if self.data in command: | |
3f302d51 | 101 | self.putx([0, ['ROM command: 0x%02x \'%s\'' |
48b59746 UH |
102 | % (self.data, command[self.data][0])]]) |
103 | self.state = command[self.data][1] | |
9cfb16e8 | 104 | else: |
3f302d51 UH |
105 | self.putx([0, ['ROM command: 0x%02x \'%s\'' |
106 | % (self.data, 'unrecognized')]]) | |
48b59746 UH |
107 | self.state = 'COMMAND ERROR' |
108 | elif self.state == 'GET ROM': | |
109 | # A 64 bit device address is selected. | |
3f302d51 | 110 | # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte) |
48b59746 UH |
111 | if self.onewire_collect(64, val, ss, es) == 0: |
112 | return | |
113 | self.rom = self.data & 0xffffffffffffffff | |
114 | self.putx([0, ['ROM: 0x%016x' % self.rom]]) | |
115 | self.puty(['ROM', self.rom]) | |
116 | self.state = 'TRANSPORT' | |
117 | elif self.state == 'SEARCH ROM': | |
118 | # A 64 bit device address is searched for. | |
3f302d51 | 119 | # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte) |
48b59746 UH |
120 | if self.onewire_search(64, val, ss, es) == 0: |
121 | return | |
122 | self.rom = self.data & 0xffffffffffffffff | |
123 | self.putx([0, ['ROM: 0x%016x' % self.rom]]) | |
124 | self.puty(['ROM', self.rom]) | |
125 | self.state = 'TRANSPORT' | |
126 | elif self.state == 'TRANSPORT': | |
127 | # The transport layer is handled in byte sized units. | |
128 | if self.onewire_collect(8, val, ss, es) == 0: | |
129 | return | |
3f302d51 | 130 | self.putx([0, ['Data: 0x%02x' % self.data]]) |
48b59746 UH |
131 | self.puty(['DATA', self.data]) |
132 | elif self.state == 'COMMAND ERROR': | |
133 | # Since the command is not recognized, print raw data. | |
134 | if self.onewire_collect(8, val, ss, es) == 0: | |
135 | return | |
3f302d51 | 136 | self.putx([0, ['ROM error data: 0x%02x' % self.data]]) |
48b59746 UH |
137 | else: |
138 | raise Exception('Invalid state: %s' % self.state) | |
9cfb16e8 | 139 | |
48b59746 | 140 | # Data collector. |
6188e4e4 UH |
141 | def onewire_collect(self, length, val, ss, es): |
142 | # Storing the sample this sequence begins with. | |
143 | if self.bit_cnt == 1: | |
48b59746 | 144 | self.beg = ss |
9cfb16e8 | 145 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) |
6188e4e4 UH |
146 | self.bit_cnt += 1 |
147 | # Storing the sample this sequence ends with. | |
148 | # In case the full length of the sequence is received, return 1. | |
149 | if self.bit_cnt == length: | |
48b59746 | 150 | self.end = es |
6188e4e4 UH |
151 | self.data = self.data & ((1 << length) - 1) |
152 | self.bit_cnt = 0 | |
153 | return 1 | |
9cfb16e8 | 154 | else: |
6188e4e4 | 155 | return 0 |
9cfb16e8 | 156 | |
48b59746 | 157 | # Search collector. |
6188e4e4 UH |
158 | def onewire_search(self, length, val, ss, es): |
159 | # Storing the sample this sequence begins with. | |
160 | if (self.bit_cnt == 0) and (self.search == 'P'): | |
48b59746 | 161 | self.beg = ss |
6188e4e4 UH |
162 | |
163 | if self.search == 'P': | |
164 | # Master receives an original address bit. | |
165 | self.data_p = self.data_p & ~(1 << self.bit_cnt) | \ | |
166 | (val << self.bit_cnt) | |
167 | self.search = 'N' | |
168 | elif self.search == 'N': | |
169 | # Master receives a complemented address bit. | |
170 | self.data_n = self.data_n & ~(1 << self.bit_cnt) | \ | |
171 | (val << self.bit_cnt) | |
172 | self.search = 'D' | |
173 | elif self.search == 'D': | |
174 | # Master transmits an address bit. | |
175 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
176 | self.search = 'P' | |
177 | self.bit_cnt += 1 | |
178 | ||
179 | # Storing the sample this sequence ends with. | |
180 | # In case the full length of the sequence is received, return 1. | |
181 | if self.bit_cnt == length: | |
48b59746 | 182 | self.end = es |
6188e4e4 UH |
183 | self.data_p = self.data_p & ((1 << length) - 1) |
184 | self.data_n = self.data_n & ((1 << length) - 1) | |
185 | self.data = self.data & ((1 << length) - 1) | |
186 | self.search = 'P' | |
187 | self.bit_cnt = 0 | |
188 | return 1 | |
9cfb16e8 | 189 | else: |
6188e4e4 | 190 | return 0 |