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9cfb16e8 | 1 | ## |
50bd5d25 | 2 | ## This file is part of the libsigrokdecode project. |
9cfb16e8 IJ |
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 | |
4539e9ca | 17 | ## along with this program; if not, see <http://www.gnu.org/licenses/>. |
9cfb16e8 IJ |
18 | ## |
19 | ||
9cfb16e8 IJ |
20 | import sigrokdecode as srd |
21 | ||
6188e4e4 | 22 | # Dictionary of ROM commands and their names, next state. |
758d2ea9 | 23 | command = { |
1fe967f2 UH |
24 | 0x33: ['Read ROM' , 'GET ROM' ], |
25 | 0x0f: ['Conditional read ROM' , 'GET ROM' ], | |
26 | 0xcc: ['Skip ROM' , 'TRANSPORT' ], | |
27 | 0x55: ['Match ROM' , 'GET ROM' ], | |
28 | 0xf0: ['Search ROM' , 'SEARCH ROM'], | |
29 | 0xec: ['Conditional search ROM', 'SEARCH ROM'], | |
30 | 0x3c: ['Overdrive skip ROM' , 'TRANSPORT' ], | |
31 | 0x69: ['Overdrive match ROM' , 'GET ROM' ], | |
b53a9138 | 32 | 0xa5: ['Resume' , 'TRANSPORT' ], |
758d2ea9 | 33 | } |
9cfb16e8 IJ |
34 | |
35 | class Decoder(srd.Decoder): | |
b197383c | 36 | api_version = 3 |
9cfb16e8 IJ |
37 | id = 'onewire_network' |
38 | name = '1-Wire network layer' | |
6188e4e4 | 39 | longname = '1-Wire serial communication bus (network layer)' |
9cfb16e8 IJ |
40 | desc = 'Bidirectional, half-duplex, asynchronous serial bus.' |
41 | license = 'gplv2+' | |
42 | inputs = ['onewire_link'] | |
43 | outputs = ['onewire_network'] | |
d6d8a8a4 | 44 | tags = ['Embedded/industrial'] |
da9bcbd9 BV |
45 | annotations = ( |
46 | ('text', 'Human-readable text'), | |
47 | ) | |
9cfb16e8 | 48 | |
92b7b49f | 49 | def __init__(self): |
10aeb8ea GS |
50 | self.reset() |
51 | ||
52 | def reset(self): | |
486b19ce UH |
53 | self.ss_block = 0 |
54 | self.es_block = 0 | |
6188e4e4 | 55 | self.state = 'COMMAND' |
9cfb16e8 | 56 | self.bit_cnt = 0 |
6188e4e4 UH |
57 | self.search = 'P' |
58 | self.data_p = 0x0 | |
59 | self.data_n = 0x0 | |
60 | self.data = 0x0 | |
48b59746 | 61 | self.rom = 0x0000000000000000 |
9cfb16e8 | 62 | |
8915b346 | 63 | def start(self): |
c515eed7 | 64 | self.out_python = self.register(srd.OUTPUT_PYTHON) |
be465111 | 65 | self.out_ann = self.register(srd.OUTPUT_ANN) |
9cfb16e8 | 66 | |
6188e4e4 UH |
67 | def putx(self, data): |
68 | # Helper function for most annotations. | |
486b19ce | 69 | self.put(self.ss_block, self.es_block, self.out_ann, data) |
6188e4e4 UH |
70 | |
71 | def puty(self, data): | |
72 | # Helper function for most protocol packets. | |
486b19ce | 73 | self.put(self.ss_block, self.es_block, self.out_python, data) |
6188e4e4 | 74 | |
9cfb16e8 | 75 | def decode(self, ss, es, data): |
6188e4e4 | 76 | code, val = data |
9cfb16e8 IJ |
77 | |
78 | # State machine. | |
6188e4e4 UH |
79 | if code == 'RESET/PRESENCE': |
80 | self.search = 'P' | |
9cfb16e8 | 81 | self.bit_cnt = 0 |
6188e4e4 | 82 | self.put(ss, es, self.out_ann, |
3f302d51 | 83 | [0, ['Reset/presence: %s' % ('true' if val else 'false')]]) |
c515eed7 | 84 | self.put(ss, es, self.out_python, ['RESET/PRESENCE', val]) |
6188e4e4 | 85 | self.state = 'COMMAND' |
48b59746 UH |
86 | return |
87 | ||
88 | # For now we're only interested in 'RESET/PRESENCE' and 'BIT' packets. | |
89 | if code != 'BIT': | |
90 | return | |
91 | ||
92 | if self.state == 'COMMAND': | |
93 | # Receiving and decoding a ROM command. | |
94 | if self.onewire_collect(8, val, ss, es) == 0: | |
95 | return | |
96 | if self.data in command: | |
3f302d51 | 97 | self.putx([0, ['ROM command: 0x%02x \'%s\'' |
48b59746 UH |
98 | % (self.data, command[self.data][0])]]) |
99 | self.state = command[self.data][1] | |
9cfb16e8 | 100 | else: |
3f302d51 UH |
101 | self.putx([0, ['ROM command: 0x%02x \'%s\'' |
102 | % (self.data, 'unrecognized')]]) | |
48b59746 UH |
103 | self.state = 'COMMAND ERROR' |
104 | elif self.state == 'GET ROM': | |
105 | # A 64 bit device address is selected. | |
3f302d51 | 106 | # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte) |
48b59746 UH |
107 | if self.onewire_collect(64, val, ss, es) == 0: |
108 | return | |
109 | self.rom = self.data & 0xffffffffffffffff | |
110 | self.putx([0, ['ROM: 0x%016x' % self.rom]]) | |
111 | self.puty(['ROM', self.rom]) | |
112 | self.state = 'TRANSPORT' | |
113 | elif self.state == 'SEARCH ROM': | |
114 | # A 64 bit device address is searched for. | |
3f302d51 | 115 | # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte) |
48b59746 UH |
116 | if self.onewire_search(64, val, ss, es) == 0: |
117 | return | |
118 | self.rom = self.data & 0xffffffffffffffff | |
119 | self.putx([0, ['ROM: 0x%016x' % self.rom]]) | |
120 | self.puty(['ROM', self.rom]) | |
121 | self.state = 'TRANSPORT' | |
122 | elif self.state == 'TRANSPORT': | |
123 | # The transport layer is handled in byte sized units. | |
124 | if self.onewire_collect(8, val, ss, es) == 0: | |
125 | return | |
3f302d51 | 126 | self.putx([0, ['Data: 0x%02x' % self.data]]) |
48b59746 UH |
127 | self.puty(['DATA', self.data]) |
128 | elif self.state == 'COMMAND ERROR': | |
129 | # Since the command is not recognized, print raw data. | |
130 | if self.onewire_collect(8, val, ss, es) == 0: | |
131 | return | |
3f302d51 | 132 | self.putx([0, ['ROM error data: 0x%02x' % self.data]]) |
9cfb16e8 | 133 | |
48b59746 | 134 | # Data collector. |
6188e4e4 UH |
135 | def onewire_collect(self, length, val, ss, es): |
136 | # Storing the sample this sequence begins with. | |
730e07bc | 137 | if self.bit_cnt == 0: |
486b19ce | 138 | self.ss_block = ss |
9cfb16e8 | 139 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) |
6188e4e4 UH |
140 | self.bit_cnt += 1 |
141 | # Storing the sample this sequence ends with. | |
142 | # In case the full length of the sequence is received, return 1. | |
143 | if self.bit_cnt == length: | |
486b19ce | 144 | self.es_block = es |
6188e4e4 UH |
145 | self.data = self.data & ((1 << length) - 1) |
146 | self.bit_cnt = 0 | |
147 | return 1 | |
9cfb16e8 | 148 | else: |
6188e4e4 | 149 | return 0 |
9cfb16e8 | 150 | |
48b59746 | 151 | # Search collector. |
6188e4e4 UH |
152 | def onewire_search(self, length, val, ss, es): |
153 | # Storing the sample this sequence begins with. | |
154 | if (self.bit_cnt == 0) and (self.search == 'P'): | |
486b19ce | 155 | self.ss_block = ss |
6188e4e4 UH |
156 | |
157 | if self.search == 'P': | |
158 | # Master receives an original address bit. | |
159 | self.data_p = self.data_p & ~(1 << self.bit_cnt) | \ | |
160 | (val << self.bit_cnt) | |
161 | self.search = 'N' | |
162 | elif self.search == 'N': | |
163 | # Master receives a complemented address bit. | |
164 | self.data_n = self.data_n & ~(1 << self.bit_cnt) | \ | |
165 | (val << self.bit_cnt) | |
166 | self.search = 'D' | |
167 | elif self.search == 'D': | |
168 | # Master transmits an address bit. | |
169 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
170 | self.search = 'P' | |
171 | self.bit_cnt += 1 | |
172 | ||
173 | # Storing the sample this sequence ends with. | |
174 | # In case the full length of the sequence is received, return 1. | |
175 | if self.bit_cnt == length: | |
486b19ce | 176 | self.es_block = es |
6188e4e4 UH |
177 | self.data_p = self.data_p & ((1 << length) - 1) |
178 | self.data_n = self.data_n & ((1 << length) - 1) | |
179 | self.data = self.data & ((1 << length) - 1) | |
180 | self.search = 'P' | |
181 | self.bit_cnt = 0 | |
182 | return 1 | |
9cfb16e8 | 183 | else: |
6188e4e4 | 184 | return 0 |