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']
44 ('text', 'Human-readable text'),
50 self.state = 'COMMAND'
56 self.rom = 0x0000000000000000
59 self.out_python = self.register(srd.OUTPUT_PYTHON)
60 self.out_ann = self.register(srd.OUTPUT_ANN)
63 # Helper function for most annotations.
64 self.put(self.ss_block, self.es_block, self.out_ann, data)
67 # Helper function for most protocol packets.
68 self.put(self.ss_block, self.es_block, self.out_python, data)
70 def decode(self, ss, es, data):
74 if code == 'RESET/PRESENCE':
77 self.put(ss, es, self.out_ann,
78 [0, ['Reset/presence: %s' % ('true' if val else 'false')]])
79 self.put(ss, es, self.out_python, ['RESET/PRESENCE', val])
80 self.state = 'COMMAND'
83 # For now we're only interested in 'RESET/PRESENCE' and 'BIT' packets.
87 if self.state == 'COMMAND':
88 # Receiving and decoding a ROM command.
89 if self.onewire_collect(8, val, ss, es) == 0:
91 if self.data in command:
92 self.putx([0, ['ROM command: 0x%02x \'%s\''
93 % (self.data, command[self.data][0])]])
94 self.state = command[self.data][1]
96 self.putx([0, ['ROM command: 0x%02x \'%s\''
97 % (self.data, 'unrecognized')]])
98 self.state = 'COMMAND ERROR'
99 elif self.state == 'GET ROM':
100 # A 64 bit device address is selected.
101 # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte)
102 if self.onewire_collect(64, val, ss, es) == 0:
104 self.rom = self.data & 0xffffffffffffffff
105 self.putx([0, ['ROM: 0x%016x' % self.rom]])
106 self.puty(['ROM', self.rom])
107 self.state = 'TRANSPORT'
108 elif self.state == 'SEARCH ROM':
109 # A 64 bit device address is searched for.
110 # Family code (1 byte) + serial number (6 bytes) + CRC (1 byte)
111 if self.onewire_search(64, val, ss, es) == 0:
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 == 'TRANSPORT':
118 # The transport layer is handled in byte sized units.
119 if self.onewire_collect(8, val, ss, es) == 0:
121 self.putx([0, ['Data: 0x%02x' % self.data]])
122 self.puty(['DATA', self.data])
123 elif self.state == 'COMMAND ERROR':
124 # Since the command is not recognized, print raw data.
125 if self.onewire_collect(8, val, ss, es) == 0:
127 self.putx([0, ['ROM error data: 0x%02x' % self.data]])
130 def onewire_collect(self, length, val, ss, es):
131 # Storing the sample this sequence begins with.
132 if self.bit_cnt == 0:
134 self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
136 # Storing the sample this sequence ends with.
137 # In case the full length of the sequence is received, return 1.
138 if self.bit_cnt == length:
140 self.data = self.data & ((1 << length) - 1)
147 def onewire_search(self, length, val, ss, es):
148 # Storing the sample this sequence begins with.
149 if (self.bit_cnt == 0) and (self.search == 'P'):
152 if self.search == 'P':
153 # Master receives an original address bit.
154 self.data_p = self.data_p & ~(1 << self.bit_cnt) | \
155 (val << self.bit_cnt)
157 elif self.search == 'N':
158 # Master receives a complemented address bit.
159 self.data_n = self.data_n & ~(1 << self.bit_cnt) | \
160 (val << self.bit_cnt)
162 elif self.search == 'D':
163 # Master transmits an address bit.
164 self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
168 # Storing the sample this sequence ends with.
169 # In case the full length of the sequence is received, return 1.
170 if self.bit_cnt == length:
172 self.data_p = self.data_p & ((1 << length) - 1)
173 self.data_n = self.data_n & ((1 << length) - 1)
174 self.data = self.data & ((1 << length) - 1)