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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 | |
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 | ||
e7720d6c | 21 | # 1-Wire protocol decoder (link layer) |
9cfb16e8 IJ |
22 | |
23 | import sigrokdecode as srd | |
24 | ||
25 | class Decoder(srd.Decoder): | |
26 | api_version = 1 | |
27 | id = 'onewire_link' | |
28 | name = '1-Wire link layer' | |
e7720d6c | 29 | longname = '1-Wire serial communication bus (link layer)' |
9cfb16e8 IJ |
30 | desc = 'Bidirectional, half-duplex, asynchronous serial bus.' |
31 | license = 'gplv2+' | |
32 | inputs = ['logic'] | |
33 | outputs = ['onewire_link'] | |
34 | probes = [ | |
3f302d51 | 35 | {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire signal line'}, |
9cfb16e8 IJ |
36 | ] |
37 | optional_probes = [ | |
3f302d51 | 38 | {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power supply pin'}, |
9cfb16e8 IJ |
39 | ] |
40 | options = { | |
e7720d6c UH |
41 | 'overdrive': ['Overdrive', 1], |
42 | # Time options (specified in number of samplerate periods): | |
43 | 'cnt_normal_bit': ['Normal mode sample bit time', 0], | |
44 | 'cnt_normal_slot': ['Normal mode data slot time', 0], | |
45 | 'cnt_normal_presence': ['Normal mode sample presence time', 0], | |
46 | 'cnt_normal_reset': ['Normal mode reset time', 0], | |
47 | 'cnt_overdrive_bit': ['Overdrive mode sample bit time', 0], | |
48 | 'cnt_overdrive_slot': ['Overdrive mode data slot time', 0], | |
49 | 'cnt_overdrive_presence': ['Overdrive mode sample presence time', 0], | |
50 | 'cnt_overdrive_reset': ['Overdrive mode reset time', 0], | |
9cfb16e8 IJ |
51 | } |
52 | annotations = [ | |
938aa7fb UH |
53 | ['bit', 'Bit'], |
54 | ['warnings', 'Warnings'], | |
55 | ['reset', 'Reset/presence'], | |
56 | ['overdrive', 'Overdrive mode notifications'], | |
9cfb16e8 IJ |
57 | ] |
58 | ||
ddeb9b32 UH |
59 | def putm(self, data): |
60 | self.put(0, 0, self.out_ann, data) | |
61 | ||
62 | def putpb(self, data): | |
63 | self.put(self.fall, self.samplenum, self.out_proto, data) | |
64 | ||
65 | def putb(self, data): | |
66 | self.put(self.fall, self.samplenum, self.out_ann, data) | |
67 | ||
68 | def putx(self, data): | |
69 | self.put(self.fall, self.cnt_bit[self.overdrive], self.out_ann, data) | |
70 | ||
9cfb16e8 | 71 | def __init__(self, **kwargs): |
9cfb16e8 | 72 | self.samplenum = 0 |
e7720d6c | 73 | self.state = 'WAIT FOR FALLING EDGE' |
9cfb16e8 | 74 | self.present = 0 |
e7720d6c | 75 | self.bit = 0 |
99f5f3b5 IJ |
76 | self.bit_cnt = 0 |
77 | self.command = 0 | |
9cfb16e8 | 78 | self.overdrive = 0 |
e7720d6c UH |
79 | self.fall = 0 |
80 | self.rise = 0 | |
9cfb16e8 IJ |
81 | |
82 | def start(self, metadata): | |
83 | self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_link') | |
e7720d6c | 84 | self.out_ann = self.add(srd.OUTPUT_ANN, 'onewire_link') |
9cfb16e8 | 85 | |
9cfb16e8 | 86 | self.samplerate = metadata['samplerate'] |
e7720d6c UH |
87 | |
88 | # Check if samplerate is appropriate. | |
89 | if self.options['overdrive']: | |
e7720d6c | 90 | if self.samplerate < 2000000: |
ddeb9b32 UH |
91 | self.putm([1, ['Sampling rate is too low. Must be above ' + |
92 | '2MHz for proper overdrive mode decoding.']]) | |
e7720d6c | 93 | elif self.samplerate < 5000000: |
ddeb9b32 UH |
94 | self.putm([1, ['Sampling rate is suggested to be above 5MHz ' + |
95 | 'for proper overdrive mode decoding.']]) | |
9cfb16e8 | 96 | else: |
e7720d6c | 97 | if self.samplerate < 400000: |
ddeb9b32 UH |
98 | self.putm([1, ['Sampling rate is too low. Must be above ' + |
99 | '400kHz for proper normal mode decoding.']]) | |
9cfb16e8 | 100 | elif (self.samplerate < 1000000): |
ddeb9b32 UH |
101 | self.putm([1, ['Sampling rate is suggested to be above ' + |
102 | '1MHz for proper normal mode decoding.']]) | |
9cfb16e8 | 103 | |
e7720d6c UH |
104 | # The default 1-Wire time base is 30us. This is used to calculate |
105 | # sampling times. | |
106 | samplerate = float(self.samplerate) | |
107 | if self.options['cnt_normal_bit']: | |
9cfb16e8 IJ |
108 | self.cnt_normal_bit = self.options['cnt_normal_bit'] |
109 | else: | |
e7720d6c UH |
110 | self.cnt_normal_bit = int(samplerate * 0.000015) - 1 # 15ns |
111 | if self.options['cnt_normal_slot']: | |
671cc300 IJ |
112 | self.cnt_normal_slot = self.options['cnt_normal_slot'] |
113 | else: | |
e7720d6c UH |
114 | self.cnt_normal_slot = int(samplerate * 0.000060) - 1 # 60ns |
115 | if self.options['cnt_normal_presence']: | |
9cfb16e8 IJ |
116 | self.cnt_normal_presence = self.options['cnt_normal_presence'] |
117 | else: | |
e7720d6c UH |
118 | self.cnt_normal_presence = int(samplerate * 0.000075) - 1 # 75ns |
119 | if self.options['cnt_normal_reset']: | |
9cfb16e8 IJ |
120 | self.cnt_normal_reset = self.options['cnt_normal_reset'] |
121 | else: | |
e7720d6c UH |
122 | self.cnt_normal_reset = int(samplerate * 0.000480) - 1 # 480ns |
123 | if self.options['cnt_overdrive_bit']: | |
9cfb16e8 IJ |
124 | self.cnt_overdrive_bit = self.options['cnt_overdrive_bit'] |
125 | else: | |
e7720d6c UH |
126 | self.cnt_overdrive_bit = int(samplerate * 0.000002) - 1 # 2ns |
127 | if self.options['cnt_overdrive_slot']: | |
671cc300 IJ |
128 | self.cnt_overdrive_slot = self.options['cnt_overdrive_slot'] |
129 | else: | |
e7720d6c UH |
130 | self.cnt_overdrive_slot = int(samplerate * 0.0000073) - 1 # 6ns+1.3ns |
131 | if self.options['cnt_overdrive_presence']: | |
9cfb16e8 IJ |
132 | self.cnt_overdrive_presence = self.options['cnt_overdrive_presence'] |
133 | else: | |
e7720d6c UH |
134 | self.cnt_overdrive_presence = int(samplerate * 0.000010) - 1 # 10ns |
135 | if self.options['cnt_overdrive_reset']: | |
9cfb16e8 IJ |
136 | self.cnt_overdrive_reset = self.options['cnt_overdrive_reset'] |
137 | else: | |
e7720d6c | 138 | self.cnt_overdrive_reset = int(samplerate * 0.000048) - 1 # 48ns |
9cfb16e8 | 139 | |
e7720d6c UH |
140 | # Organize values into lists. |
141 | self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit] | |
9cfb16e8 | 142 | self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence] |
e7720d6c UH |
143 | self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset] |
144 | self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot] | |
145 | ||
146 | # Check if sample times are in the allowed range. | |
147 | ||
148 | time_min = float(self.cnt_normal_bit) / self.samplerate | |
149 | time_max = float(self.cnt_normal_bit + 1) / self.samplerate | |
150 | if (time_min < 0.000005) or (time_max > 0.000015): | |
ddeb9b32 | 151 | self.putm([1, ['The normal mode data sample time interval ' + |
e7720d6c UH |
152 | '(%2.1fus-%2.1fus) should be inside (5.0us, 15.0us).' |
153 | % (time_min * 1000000, time_max * 1000000)]]) | |
154 | ||
155 | time_min = float(self.cnt_normal_presence) / self.samplerate | |
156 | time_max = float(self.cnt_normal_presence + 1) / self.samplerate | |
157 | if (time_min < 0.0000681) or (time_max > 0.000075): | |
ddeb9b32 | 158 | self.putm([1, ['The normal mode presence sample time interval ' + |
e7720d6c UH |
159 | '(%2.1fus-%2.1fus) should be inside (68.1us, 75.0us).' |
160 | % (time_min * 1000000, time_max * 1000000)]]) | |
161 | ||
162 | time_min = float(self.cnt_overdrive_bit) / self.samplerate | |
163 | time_max = float(self.cnt_overdrive_bit + 1) / self.samplerate | |
164 | if (time_min < 0.000001) or (time_max > 0.000002): | |
ddeb9b32 | 165 | self.putm([1, ['The overdrive mode data sample time interval ' + |
e7720d6c UH |
166 | '(%2.1fus-%2.1fus) should be inside (1.0us, 2.0us).' |
167 | % (time_min * 1000000, time_max * 1000000)]]) | |
168 | ||
169 | time_min = float(self.cnt_overdrive_presence) / self.samplerate | |
170 | time_max = float(self.cnt_overdrive_presence + 1) / self.samplerate | |
171 | if (time_min < 0.0000073) or (time_max > 0.000010): | |
ddeb9b32 | 172 | self.putm([1, ['The overdrive mode presence sample time interval ' + |
e7720d6c UH |
173 | '(%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).' |
174 | % (time_min*1000000, time_max*1000000)]]) | |
9cfb16e8 IJ |
175 | |
176 | def report(self): | |
177 | pass | |
178 | ||
179 | def decode(self, ss, es, data): | |
180 | for (self.samplenum, (owr, pwr)) in data: | |
9cfb16e8 IJ |
181 | # State machine. |
182 | if self.state == 'WAIT FOR FALLING EDGE': | |
183 | # The start of a cycle is a falling edge. | |
48b59746 UH |
184 | if owr != 0: |
185 | continue | |
186 | # Save the sample number for the falling edge. | |
187 | self.fall = self.samplenum | |
188 | # Go to waiting for sample time. | |
189 | self.state = 'WAIT FOR DATA SAMPLE' | |
9cfb16e8 | 190 | elif self.state == 'WAIT FOR DATA SAMPLE': |
e7720d6c UH |
191 | # Sample data bit. |
192 | t = self.samplenum - self.fall | |
193 | if t == self.cnt_bit[self.overdrive]: | |
194 | self.bit = owr | |
671cc300 IJ |
195 | self.state = 'WAIT FOR DATA SLOT END' |
196 | elif self.state == 'WAIT FOR DATA SLOT END': | |
e7720d6c UH |
197 | # A data slot ends in a recovery period, otherwise, this is |
198 | # probably a reset. | |
199 | t = self.samplenum - self.fall | |
48b59746 UH |
200 | if t != self.cnt_slot[self.overdrive]: |
201 | continue | |
202 | ||
203 | if owr == 0: | |
204 | # This seems to be a reset slot, wait for its end. | |
205 | self.state = 'WAIT FOR RISING EDGE' | |
206 | continue | |
207 | ||
ddeb9b32 UH |
208 | self.putb([0, ['Bit: %d' % self.bit]]) |
209 | self.putpb(['BIT', self.bit]) | |
e7720d6c | 210 | |
48b59746 UH |
211 | # Checking the first command to see if overdrive mode |
212 | # should be entered. | |
213 | if self.bit_cnt <= 8: | |
214 | self.command |= (self.bit << self.bit_cnt) | |
215 | elif self.bit_cnt == 8 and self.command in [0x3c, 0x69]: | |
938aa7fb | 216 | self.putx([3, ['Entering overdrive mode']]) |
48b59746 UH |
217 | # Increment the bit counter. |
218 | self.bit_cnt += 1 | |
219 | # Wait for next slot. | |
220 | self.state = 'WAIT FOR FALLING EDGE' | |
9cfb16e8 IJ |
221 | elif self.state == 'WAIT FOR RISING EDGE': |
222 | # The end of a cycle is a rising edge. | |
48b59746 UH |
223 | if owr != 1: |
224 | continue | |
225 | ||
226 | # Check if this was a reset cycle. | |
227 | t = self.samplenum - self.fall | |
228 | if t > self.cnt_normal_reset: | |
229 | # Save the sample number for the falling edge. | |
230 | self.rise = self.samplenum | |
231 | self.state = 'WAIT FOR PRESENCE DETECT' | |
232 | # Exit overdrive mode. | |
233 | if self.overdrive: | |
938aa7fb | 234 | self.putx([3, ['Exiting overdrive mode']]) |
48b59746 UH |
235 | self.overdrive = 0 |
236 | # Clear command bit counter and data register. | |
237 | self.bit_cnt = 0 | |
238 | self.command = 0 | |
239 | elif (t > self.cnt_overdrive_reset) and self.overdrive: | |
240 | # Save the sample number for the falling edge. | |
241 | self.rise = self.samplenum | |
242 | self.state = "WAIT FOR PRESENCE DETECT" | |
243 | # Otherwise this is assumed to be a data bit. | |
244 | else: | |
245 | self.state = "WAIT FOR FALLING EDGE" | |
9cfb16e8 | 246 | elif self.state == 'WAIT FOR PRESENCE DETECT': |
e7720d6c UH |
247 | # Sample presence status. |
248 | t = self.samplenum - self.rise | |
249 | if t == self.cnt_presence[self.overdrive]: | |
671cc300 IJ |
250 | self.present = owr |
251 | self.state = 'WAIT FOR RESET SLOT END' | |
252 | elif self.state == 'WAIT FOR RESET SLOT END': | |
48b59746 | 253 | # A reset slot ends in a long recovery period. |
e7720d6c | 254 | t = self.samplenum - self.rise |
48b59746 UH |
255 | if t != self.cnt_reset[self.overdrive]: |
256 | continue | |
257 | ||
258 | if owr == 0: | |
259 | # This seems to be a reset slot, wait for its end. | |
260 | self.state = 'WAIT FOR RISING EDGE' | |
261 | continue | |
262 | ||
ddeb9b32 | 263 | p = 'false' if self.present else 'true' |
938aa7fb | 264 | self.putb([2, ['Reset/presence: %s' % p]]) |
ddeb9b32 UH |
265 | self.putpb(['RESET/PRESENCE', not self.present]) |
266 | ||
48b59746 UH |
267 | # Wait for next slot. |
268 | self.state = 'WAIT FOR FALLING EDGE' | |
9cfb16e8 | 269 | else: |
e7720d6c | 270 | raise Exception('Invalid state: %s' % self.state) |