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, write to the Free Software
18 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 import sigrokdecode as srd
23 class Decoder(srd.Decoder):
26 name = '1-Wire link layer'
27 longname = '1-Wire serial communication bus (link layer)'
28 desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
31 outputs = ['onewire_link']
33 {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire signal line'},
36 {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power supply pin'},
40 'desc': 'Overdrive mode', 'default': 'no', 'values': ('yes', 'no')},
41 # Time options (specified in microseconds):
42 {'id': 'cnt_normal_bit',
43 'desc': 'Normal mode sample bit time (μs)', 'default': 15},
44 {'id': 'cnt_normal_slot',
45 'desc': 'Normal mode data slot time (μs)', 'default': 60},
46 {'id': 'cnt_normal_presence',
47 'desc': 'Normal mode sample presence time (μs)', 'default': 75},
48 {'id': 'cnt_normal_reset',
49 'desc': 'Normal mode reset time (μs)', 'default': 480},
50 {'id': 'cnt_overdrive_bit',
51 'desc': 'Overdrive mode sample bit time (μs)', 'default': 2},
52 {'id': 'cnt_overdrive_slot',
53 'desc': 'Overdrive mode data slot time (μs)', 'default': 7.3},
54 {'id': 'cnt_overdrive_presence',
55 'desc': 'Overdrive mode sample presence time (μs)', 'default': 10},
56 {'id': 'cnt_overdrive_reset',
57 'desc': 'Overdrive mode reset time (μs)', 'default': 48},
61 ('warnings', 'Warnings'),
63 ('presence', 'Presence'),
64 ('overdrive', 'Overdrive mode notifications'),
67 ('bits', 'Bits', (0, 2, 3)),
68 ('info', 'Info', (4,)),
69 ('warnings', 'Warnings', (1,)),
73 self.put(0, 0, self.out_ann, data)
75 def putpb(self, data):
76 self.put(self.fall, self.samplenum, self.out_python, data)
79 self.put(self.fall, self.samplenum, self.out_ann, data)
82 self.put(self.fall, self.cnt_bit[self.overdrive], self.out_ann, data)
84 def putfr(self, data):
85 self.put(self.fall, self.rise, self.out_ann, data)
87 def putprs(self, data):
88 self.put(self.rise, self.samplenum, self.out_python, data)
90 def putrs(self, data):
91 self.put(self.rise, self.samplenum, self.out_ann, data)
93 def __init__(self, **kwargs):
94 self.samplerate = None
96 self.state = 'WAIT FOR FALLING EDGE'
106 self.out_python = self.register(srd.OUTPUT_PYTHON)
107 self.out_ann = self.register(srd.OUTPUT_ANN)
109 def metadata(self, key, value):
110 if key != srd.SRD_CONF_SAMPLERATE:
112 self.samplerate = value
114 # Check if samplerate is appropriate.
115 if self.options['overdrive'] == 'yes':
116 if self.samplerate < 2000000:
117 self.putm([1, ['Sampling rate is too low. Must be above ' +
118 '2MHz for proper overdrive mode decoding.']])
119 elif self.samplerate < 5000000:
120 self.putm([1, ['Sampling rate is suggested to be above 5MHz ' +
121 'for proper overdrive mode decoding.']])
123 if self.samplerate < 400000:
124 self.putm([1, ['Sampling rate is too low. Must be above ' +
125 '400kHz for proper normal mode decoding.']])
126 elif (self.samplerate < 1000000):
127 self.putm([1, ['Sampling rate is suggested to be above ' +
128 '1MHz for proper normal mode decoding.']])
130 # The default 1-Wire time base is 30us. This is used to calculate
132 samplerate = float(self.samplerate)
134 x = float(self.options['cnt_normal_bit']) / 1000000.0
135 self.cnt_normal_bit = int(samplerate * x) - 1
136 x = float(self.options['cnt_normal_slot']) / 1000000.0
137 self.cnt_normal_slot = int(samplerate * x) - 1
138 x = float(self.options['cnt_normal_presence']) / 1000000.0
139 self.cnt_normal_presence = int(samplerate * x) - 1
140 x = float(self.options['cnt_normal_reset']) / 1000000.0
141 self.cnt_normal_reset = int(samplerate * x) - 1
142 x = float(self.options['cnt_overdrive_bit']) / 1000000.0
143 self.cnt_overdrive_bit = int(samplerate * x) - 1
144 x = float(self.options['cnt_overdrive_slot']) / 1000000.0
145 self.cnt_overdrive_slot = int(samplerate * x) - 1
146 x = float(self.options['cnt_overdrive_presence']) / 1000000.0
147 self.cnt_overdrive_presence = int(samplerate * x) - 1
148 x = float(self.options['cnt_overdrive_reset']) / 1000000.0
149 self.cnt_overdrive_reset = int(samplerate * x) - 1
151 # Organize values into lists.
152 self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit]
153 self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence]
154 self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset]
155 self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot]
157 # Check if sample times are in the allowed range.
159 time_min = float(self.cnt_normal_bit) / self.samplerate
160 time_max = float(self.cnt_normal_bit + 1) / self.samplerate
161 if (time_min < 0.000005) or (time_max > 0.000015):
162 self.putm([1, ['The normal mode data sample time interval ' +
163 '(%2.1fus-%2.1fus) should be inside (5.0us, 15.0us).'
164 % (time_min * 1000000, time_max * 1000000)]])
166 time_min = float(self.cnt_normal_presence) / self.samplerate
167 time_max = float(self.cnt_normal_presence + 1) / self.samplerate
168 if (time_min < 0.0000681) or (time_max > 0.000075):
169 self.putm([1, ['The normal mode presence sample time interval ' +
170 '(%2.1fus-%2.1fus) should be inside (68.1us, 75.0us).'
171 % (time_min * 1000000, time_max * 1000000)]])
173 time_min = float(self.cnt_overdrive_bit) / self.samplerate
174 time_max = float(self.cnt_overdrive_bit + 1) / self.samplerate
175 if (time_min < 0.000001) or (time_max > 0.000002):
176 self.putm([1, ['The overdrive mode data sample time interval ' +
177 '(%2.1fus-%2.1fus) should be inside (1.0us, 2.0us).'
178 % (time_min * 1000000, time_max * 1000000)]])
180 time_min = float(self.cnt_overdrive_presence) / self.samplerate
181 time_max = float(self.cnt_overdrive_presence + 1) / self.samplerate
182 if (time_min < 0.0000073) or (time_max > 0.000010):
183 self.putm([1, ['The overdrive mode presence sample time interval ' +
184 '(%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).'
185 % (time_min*1000000, time_max*1000000)]])
187 def decode(self, ss, es, data):
188 if self.samplerate is None:
189 raise Exception("Cannot decode without samplerate.")
190 for (self.samplenum, (owr, pwr)) in data:
192 if self.state == 'WAIT FOR FALLING EDGE':
193 # The start of a cycle is a falling edge.
196 # Save the sample number for the falling edge.
197 self.fall = self.samplenum
198 # Go to waiting for sample time.
199 self.state = 'WAIT FOR DATA SAMPLE'
200 elif self.state == 'WAIT FOR DATA SAMPLE':
202 t = self.samplenum - self.fall
203 if t == self.cnt_bit[self.overdrive]:
205 self.state = 'WAIT FOR DATA SLOT END'
206 elif self.state == 'WAIT FOR DATA SLOT END':
207 # A data slot ends in a recovery period, otherwise, this is
209 t = self.samplenum - self.fall
210 if t != self.cnt_slot[self.overdrive]:
214 # This seems to be a reset slot, wait for its end.
215 self.state = 'WAIT FOR RISING EDGE'
218 self.putb([0, ['Bit: %d' % self.bit, '%d' % self.bit]])
219 self.putpb(['BIT', self.bit])
221 # Checking the first command to see if overdrive mode
223 if self.bit_cnt <= 8:
224 self.command |= (self.bit << self.bit_cnt)
225 elif self.bit_cnt == 8 and self.command in [0x3c, 0x69]:
226 self.putx([4, ['Entering overdrive mode', 'Overdrive on']])
227 # Increment the bit counter.
229 # Wait for next slot.
230 self.state = 'WAIT FOR FALLING EDGE'
231 elif self.state == 'WAIT FOR RISING EDGE':
232 # The end of a cycle is a rising edge.
236 # Check if this was a reset cycle.
237 t = self.samplenum - self.fall
238 if t > self.cnt_normal_reset:
239 # Save the sample number for the rising edge.
240 self.rise = self.samplenum
241 self.putfr([2, ['Reset', 'Rst', 'R']])
242 self.state = 'WAIT FOR PRESENCE DETECT'
243 # Exit overdrive mode.
245 self.putx([4, ['Exiting overdrive mode', 'Overdrive off']])
247 # Clear command bit counter and data register.
250 elif (t > self.cnt_overdrive_reset) and self.overdrive:
251 # Save the sample number for the rising edge.
252 self.rise = self.samplenum
253 self.putfr([2, ['Reset', 'Rst', 'R']])
254 self.state = "WAIT FOR PRESENCE DETECT"
255 # Otherwise this is assumed to be a data bit.
257 self.state = "WAIT FOR FALLING EDGE"
258 elif self.state == 'WAIT FOR PRESENCE DETECT':
259 # Sample presence status.
260 t = self.samplenum - self.rise
261 if t == self.cnt_presence[self.overdrive]:
263 self.state = 'WAIT FOR RESET SLOT END'
264 elif self.state == 'WAIT FOR RESET SLOT END':
265 # A reset slot ends in a long recovery period.
266 t = self.samplenum - self.rise
267 if t != self.cnt_reset[self.overdrive]:
271 # This seems to be a reset slot, wait for its end.
272 self.state = 'WAIT FOR RISING EDGE'
275 p = 'false' if self.present else 'true'
276 self.putrs([3, ['Presence: %s' % p, 'Presence', 'Pres', 'P']])
277 self.putprs(['RESET/PRESENCE', not self.present])
279 # Wait for next slot.
280 self.state = 'WAIT FOR FALLING EDGE'
282 raise Exception('Invalid state: %s' % self.state)