2 ## This file is part of the libsigrokdecode project.
4 ## Copyright (C) 2012 Iztok Jeras <iztok.jeras@gmail.com>
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.
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.
16 ## You should have received a copy of the GNU General Public License
17 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
20 import sigrokdecode as srd
22 # Dictionary of ROM commands and their names, next state.
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' ],
34 class Decoder(srd.Decoder):
36 id = 'onewire_network'
37 name = '1-Wire network layer'
38 longname = '1-Wire serial communication bus (network layer)'
39 desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
41 inputs = ['onewire_link']
42 outputs = ['onewire_network']
43 tags = ['Embedded/industrial']
45 ('text', 'Human-readable text'),
54 self.state = 'COMMAND'
60 self.rom = 0x0000000000000000
63 self.out_python = self.register(srd.OUTPUT_PYTHON)
64 self.out_ann = self.register(srd.OUTPUT_ANN)
67 # Helper function for most annotations.
68 self.put(self.ss_block, self.es_block, self.out_ann, data)
71 # Helper function for most protocol packets.
72 self.put(self.ss_block, self.es_block, self.out_python, data)
74 def decode(self, ss, es, data):
78 if code == 'RESET/PRESENCE':
81 self.put(ss, es, self.out_ann,
82 [0, ['Reset/presence: %s' % ('true' if val else 'false')]])
83 self.put(ss, es, self.out_python, ['RESET/PRESENCE', val])
84 self.state = 'COMMAND'
87 # For now we're only interested in 'RESET/PRESENCE' and 'BIT' packets.
91 if self.state == 'COMMAND':
92 # Receiving and decoding a ROM command.
93 if self.onewire_collect(8, val, ss, es) == 0:
95 if self.data in command:
96 self.putx([0, ['ROM command: 0x%02x \'%s\''
97 % (self.data, command[self.data][0])]])
98 self.state = command[self.data][1]
100 self.putx([0, ['ROM command: 0x%02x \'%s\''
101 % (self.data, 'unrecognized')]])
102 self.state = 'COMMAND ERROR'
103 elif self.state == 'GET ROM':
104 # A 64 bit device address is selected.
105 # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte)
106 if self.onewire_collect(64, val, ss, es) == 0:
108 self.rom = self.data & 0xffffffffffffffff
109 self.putx([0, ['ROM: 0x%016x' % self.rom]])
110 self.puty(['ROM', self.rom])
111 self.state = 'TRANSPORT'
112 elif self.state == 'SEARCH ROM':
113 # A 64 bit device address is searched for.
114 # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte)
115 if self.onewire_search(64, val, ss, es) == 0:
117 self.rom = self.data & 0xffffffffffffffff
118 self.putx([0, ['ROM: 0x%016x' % self.rom]])
119 self.puty(['ROM', self.rom])
120 self.state = 'TRANSPORT'
121 elif self.state == 'TRANSPORT':
122 # The transport layer is handled in byte sized units.
123 if self.onewire_collect(8, val, ss, es) == 0:
125 self.putx([0, ['Data: 0x%02x' % self.data]])
126 self.puty(['DATA', self.data])
127 elif self.state == 'COMMAND ERROR':
128 # Since the command is not recognized, print raw data.
129 if self.onewire_collect(8, val, ss, es) == 0:
131 self.putx([0, ['ROM error data: 0x%02x' % self.data]])
134 def onewire_collect(self, length, val, ss, es):
135 # Storing the sample this sequence begins with.
136 if self.bit_cnt == 0:
138 self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
140 # Storing the sample this sequence ends with.
141 # In case the full length of the sequence is received, return 1.
142 if self.bit_cnt == length:
144 self.data = self.data & ((1 << length) - 1)
151 def onewire_search(self, length, val, ss, es):
152 # Storing the sample this sequence begins with.
153 if (self.bit_cnt == 0) and (self.search == 'P'):
156 if self.search == 'P':
157 # Master receives an original address bit.
158 self.data_p = self.data_p & ~(1 << self.bit_cnt) | \
159 (val << self.bit_cnt)
161 elif self.search == 'N':
162 # Master receives a complemented address bit.
163 self.data_n = self.data_n & ~(1 << self.bit_cnt) | \
164 (val << self.bit_cnt)
166 elif self.search == 'D':
167 # Master transmits an address bit.
168 self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
172 # Storing the sample this sequence ends with.
173 # In case the full length of the sequence is received, return 1.
174 if self.bit_cnt == length:
176 self.data_p = self.data_p & ((1 << length) - 1)
177 self.data_n = self.data_n & ((1 << length) - 1)
178 self.data = self.data & ((1 << length) - 1)