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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 | ||
21 | # 1-Wire protocol decoder | |
22 | ||
23 | import sigrokdecode as srd | |
24 | ||
a81787f6 IJ |
25 | # a dictionary of ROM commands and their names, next state |
26 | command = {0x33: ["READ ROM" , "GET ROM" ], | |
27 | 0x0f: ["CONDITIONAL READ ROM" , "GET ROM" ], | |
28 | 0xcc: ["SKIP ROM" , "TRANSPORT" ], | |
29 | 0x55: ["MATCH ROM" , "GET ROM" ], | |
30 | 0xf0: ["SEARCH ROM" , "SEARCH ROM"], | |
31 | 0xec: ["CONDITIONAL SEARCH ROM", "SEARCH ROM"], | |
32 | 0x3c: ["OVERDRIVE SKIP ROM" , "TRANSPORT" ], | |
33 | 0x6d: ["OVERDRIVE MATCH ROM" , "GET ROM" ]} | |
9cfb16e8 IJ |
34 | |
35 | class Decoder(srd.Decoder): | |
36 | api_version = 1 | |
37 | id = 'onewire_network' | |
38 | name = '1-Wire network layer' | |
39 | longname = '1-Wire serial communication bus' | |
40 | desc = 'Bidirectional, half-duplex, asynchronous serial bus.' | |
41 | license = 'gplv2+' | |
42 | inputs = ['onewire_link'] | |
43 | outputs = ['onewire_network'] | |
44 | probes = [] | |
45 | optional_probes = [] | |
46 | options = {} | |
47 | annotations = [ | |
48 | ['Network', 'Network layer events (device addressing)'], | |
9cfb16e8 IJ |
49 | ] |
50 | ||
51 | def __init__(self, **kwargs): | |
52 | # Event timing variables | |
53 | self.net_beg = 0 | |
54 | self.net_end = 0 | |
55 | # Network layer variables | |
56 | self.state = 'COMMAND' | |
57 | self.bit_cnt = 0 | |
58 | self.search = "P" | |
59 | self.data_p = 0x0 | |
60 | self.data_n = 0x0 | |
61 | self.data = 0x0 | |
62 | self.net_rom = 0x0000000000000000 | |
63 | ||
64 | def start(self, metadata): | |
65 | self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_network') | |
66 | self.out_ann = self.add(srd.OUTPUT_ANN , 'onewire_network') | |
67 | ||
68 | def report(self): | |
69 | pass | |
70 | ||
71 | def decode(self, ss, es, data): | |
72 | [code, val] = data | |
73 | ||
74 | # State machine. | |
e540618c | 75 | if (code == "RESET/PRESENCE"): |
9cfb16e8 IJ |
76 | self.search = "P" |
77 | self.bit_cnt = 0 | |
a81787f6 IJ |
78 | self.put(ss, es, self.out_ann, [0, ['RESET/PRESENCE: %s' % ('True' if val else 'False')]]) |
79 | self.put(ss, es, self.out_proto, ['RESET/PRESENCE', val]) | |
80 | self.state = "COMMAND" | |
99f5f3b5 | 81 | elif (code == "BIT"): |
9cfb16e8 IJ |
82 | if (self.state == "COMMAND"): |
83 | # Receiving and decoding a ROM command | |
99f5f3b5 | 84 | if (self.onewire_collect(8, val, ss, es)): |
a81787f6 IJ |
85 | if (self.data in command): |
86 | self.put(self.net_beg, self.net_end, self.out_ann, [0, | |
87 | ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, command[self.data][0])]]) | |
88 | self.state = command[self.data][1] | |
89 | else: | |
90 | self.put(self.net_beg, self.net_end, self.out_ann, [0, | |
91 | ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, 'UNRECOGNIZED')]]) | |
92 | self.state = "COMMAND ERROR" | |
9cfb16e8 IJ |
93 | elif (self.state == "GET ROM"): |
94 | # A 64 bit device address is selected | |
95 | # family code (1B) + serial number (6B) + CRC (1B) | |
99f5f3b5 | 96 | if (self.onewire_collect(64, val, ss, es)): |
9cfb16e8 | 97 | self.net_rom = self.data & 0xffffffffffffffff |
a81787f6 IJ |
98 | self.put(self.net_beg, self.net_end, self.out_ann, [0, ['ROM: 0x%016x' % self.net_rom]]) |
99 | self.put(self.net_beg, self.net_end, self.out_proto, ['ROM', self.net_rom]) | |
9cfb16e8 IJ |
100 | self.state = "TRANSPORT" |
101 | elif (self.state == "SEARCH ROM"): | |
102 | # A 64 bit device address is searched for | |
103 | # family code (1B) + serial number (6B) + CRC (1B) | |
99f5f3b5 | 104 | if (self.onewire_search(64, val, ss, es)): |
9cfb16e8 | 105 | self.net_rom = self.data & 0xffffffffffffffff |
a81787f6 IJ |
106 | self.put(self.net_beg, self.net_end, self.out_ann, [0, ['ROM: 0x%016x' % self.net_rom]]) |
107 | self.put(self.net_beg, self.net_end, self.out_proto, ['ROM', self.net_rom]) | |
9cfb16e8 IJ |
108 | self.state = "TRANSPORT" |
109 | elif (self.state == "TRANSPORT"): | |
110 | # The transport layer is handled in byte sized units | |
99f5f3b5 | 111 | if (self.onewire_collect(8, val, ss, es)): |
a81787f6 IJ |
112 | self.put(self.net_beg, self.net_end, self.out_ann, [0, ['DATA: 0x%02x' % self.data]]) |
113 | self.put(self.net_beg, self.net_end, self.out_proto, ['DATA', self.data]) | |
114 | elif (self.state == "COMMAND ERROR"): | |
115 | # Since the command is not recognized, print raw data | |
116 | if (self.onewire_collect(8, val, ss, es)): | |
117 | self.put(self.net_beg, self.net_end, self.out_ann, [0, ['ROM ERROR DATA: 0x%02x' % self.data]]) | |
9cfb16e8 IJ |
118 | else: |
119 | raise Exception('Invalid state: %s' % self.state) | |
120 | ||
121 | ||
122 | # Link/Network layer data collector | |
99f5f3b5 | 123 | def onewire_collect (self, length, val, ss, es): |
9cfb16e8 IJ |
124 | # Storing the sampe this sequence begins with |
125 | if (self.bit_cnt == 1): | |
99f5f3b5 | 126 | self.net_beg = ss |
9cfb16e8 IJ |
127 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) |
128 | self.bit_cnt = self.bit_cnt + 1 | |
129 | # Storing the sampe this sequence ends with | |
130 | # In case the full length of the sequence is received, return 1 | |
131 | if (self.bit_cnt == length): | |
99f5f3b5 | 132 | self.net_end = es |
9cfb16e8 IJ |
133 | self.data = self.data & ((1<<length)-1) |
134 | self.bit_cnt = 0 | |
135 | return (1) | |
136 | else: | |
137 | return (0) | |
138 | ||
139 | # Link/Network layer search collector | |
99f5f3b5 | 140 | def onewire_search (self, length, val, ss, es): |
9cfb16e8 IJ |
141 | # Storing the sampe this sequence begins with |
142 | if ((self.bit_cnt == 0) and (self.search == "P")): | |
99f5f3b5 | 143 | self.net_beg = ss |
9cfb16e8 IJ |
144 | # Master receives an original address bit |
145 | if (self.search == "P"): | |
146 | self.data_p = self.data_p & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
147 | self.search = "N" | |
148 | # Master receives a complemented address bit | |
149 | elif (self.search == "N"): | |
150 | self.data_n = self.data_n & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
151 | self.search = "D" | |
152 | # Master transmits an address bit | |
153 | elif (self.search == "D"): | |
154 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
155 | self.search = "P" | |
156 | self.bit_cnt = self.bit_cnt + 1 | |
157 | # Storing the sampe this sequence ends with | |
158 | # In case the full length of the sequence is received, return 1 | |
159 | if (self.bit_cnt == length): | |
99f5f3b5 | 160 | self.net_end = es |
9cfb16e8 IJ |
161 | self.data_p = self.data_p & ((1<<length)-1) |
162 | self.data_n = self.data_n & ((1<<length)-1) | |
163 | self.data = self.data & ((1<<length)-1) | |
164 | self.search = "P" | |
165 | self.bit_cnt = 0 | |
166 | return (1) | |
167 | else: | |
168 | return (0) |