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1 | ## | |
2 | ## This file is part of the libsigrokdecode 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 | import sigrokdecode as srd | |
22 | ||
23 | class Decoder(srd.Decoder): | |
24 | api_version = 1 | |
25 | id = 'onewire_link' | |
26 | name = '1-Wire link layer' | |
27 | longname = '1-Wire serial communication bus (link layer)' | |
28 | desc = 'Bidirectional, half-duplex, asynchronous serial bus.' | |
29 | license = 'gplv2+' | |
30 | inputs = ['logic'] | |
31 | outputs = ['onewire_link'] | |
32 | probes = ( | |
33 | {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire signal line'}, | |
34 | ) | |
35 | optional_probes = ( | |
36 | {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power supply pin'}, | |
37 | ) | |
38 | options = ( | |
39 | {'id': 'overdrive', | |
40 | 'desc': 'Overdrive mode', | |
41 | 'default': 'no'}, | |
42 | # Time options (specified in microseconds): | |
43 | {'id': 'cnt_normal_bit', | |
44 | 'desc': 'Normal mode sample bit time (μs)', | |
45 | 'default': 15}, | |
46 | {'id': 'cnt_normal_slot', | |
47 | 'desc': 'Normal mode data slot time (μs)', | |
48 | 'default': 60}, | |
49 | {'id': 'cnt_normal_presence', | |
50 | 'desc': 'Normal mode sample presence time (μs)', | |
51 | 'default': 75}, | |
52 | {'id': 'cnt_normal_reset', | |
53 | 'desc': 'Normal mode reset time (μs)', | |
54 | 'default': 480}, | |
55 | {'id': 'cnt_overdrive_bit', | |
56 | 'desc': 'Overdrive mode sample bit time (μs)', | |
57 | 'default': 2}, | |
58 | {'id': 'cnt_overdrive_slot', | |
59 | 'desc': 'Overdrive mode data slot time (μs)', | |
60 | 'default': 7.3}, | |
61 | {'id': 'cnt_overdrive_presence', | |
62 | 'desc': 'Overdrive mode sample presence time (μs)', | |
63 | 'default': 10}, | |
64 | {'id': 'cnt_overdrive_reset', | |
65 | 'desc': 'Overdrive mode reset time (μs)', | |
66 | 'default': 48}, | |
67 | ) | |
68 | annotations = ( | |
69 | ('bit', 'Bit'), | |
70 | ('warnings', 'Warnings'), | |
71 | ('reset', 'Reset'), | |
72 | ('presence', 'Presence'), | |
73 | ('overdrive', 'Overdrive mode notifications'), | |
74 | ) | |
75 | annotation_rows = ( | |
76 | ('bits', 'Bits', (0, 2, 3)), | |
77 | ('info', 'Info', (4,)), | |
78 | ('warnings', 'Warnings', (1,)), | |
79 | ) | |
80 | ||
81 | def putm(self, data): | |
82 | self.put(0, 0, self.out_ann, data) | |
83 | ||
84 | def putpb(self, data): | |
85 | self.put(self.fall, self.samplenum, self.out_python, data) | |
86 | ||
87 | def putb(self, data): | |
88 | self.put(self.fall, self.samplenum, self.out_ann, data) | |
89 | ||
90 | def putx(self, data): | |
91 | self.put(self.fall, self.cnt_bit[self.overdrive], self.out_ann, data) | |
92 | ||
93 | def putfr(self, data): | |
94 | self.put(self.fall, self.rise, self.out_ann, data) | |
95 | ||
96 | def putprs(self, data): | |
97 | self.put(self.rise, self.samplenum, self.out_python, data) | |
98 | ||
99 | def putrs(self, data): | |
100 | self.put(self.rise, self.samplenum, self.out_ann, data) | |
101 | ||
102 | def __init__(self, **kwargs): | |
103 | self.samplerate = None | |
104 | self.samplenum = 0 | |
105 | self.state = 'WAIT FOR FALLING EDGE' | |
106 | self.present = 0 | |
107 | self.bit = 0 | |
108 | self.bit_cnt = 0 | |
109 | self.command = 0 | |
110 | self.overdrive = 0 | |
111 | self.fall = 0 | |
112 | self.rise = 0 | |
113 | ||
114 | def start(self): | |
115 | self.out_python = self.register(srd.OUTPUT_PYTHON) | |
116 | self.out_ann = self.register(srd.OUTPUT_ANN) | |
117 | ||
118 | def metadata(self, key, value): | |
119 | if key != srd.SRD_CONF_SAMPLERATE: | |
120 | return | |
121 | self.samplerate = value | |
122 | ||
123 | # Check if samplerate is appropriate. | |
124 | if self.options['overdrive'] == 'yes': | |
125 | if self.samplerate < 2000000: | |
126 | self.putm([1, ['Sampling rate is too low. Must be above ' + | |
127 | '2MHz for proper overdrive mode decoding.']]) | |
128 | elif self.samplerate < 5000000: | |
129 | self.putm([1, ['Sampling rate is suggested to be above 5MHz ' + | |
130 | 'for proper overdrive mode decoding.']]) | |
131 | else: | |
132 | if self.samplerate < 400000: | |
133 | self.putm([1, ['Sampling rate is too low. Must be above ' + | |
134 | '400kHz for proper normal mode decoding.']]) | |
135 | elif (self.samplerate < 1000000): | |
136 | self.putm([1, ['Sampling rate is suggested to be above ' + | |
137 | '1MHz for proper normal mode decoding.']]) | |
138 | ||
139 | # The default 1-Wire time base is 30us. This is used to calculate | |
140 | # sampling times. | |
141 | samplerate = float(self.samplerate) | |
142 | ||
143 | x = float(self.options['cnt_normal_bit']) / 1000000.0 | |
144 | self.cnt_normal_bit = int(samplerate * x) - 1 | |
145 | x = float(self.options['cnt_normal_slot']) / 1000000.0 | |
146 | self.cnt_normal_slot = int(samplerate * x) - 1 | |
147 | x = float(self.options['cnt_normal_presence']) / 1000000.0 | |
148 | self.cnt_normal_presence = int(samplerate * x) - 1 | |
149 | x = float(self.options['cnt_normal_reset']) / 1000000.0 | |
150 | self.cnt_normal_reset = int(samplerate * x) - 1 | |
151 | x = float(self.options['cnt_overdrive_bit']) / 1000000.0 | |
152 | self.cnt_overdrive_bit = int(samplerate * x) - 1 | |
153 | x = float(self.options['cnt_overdrive_slot']) / 1000000.0 | |
154 | self.cnt_overdrive_slot = int(samplerate * x) - 1 | |
155 | x = float(self.options['cnt_overdrive_presence']) / 1000000.0 | |
156 | self.cnt_overdrive_presence = int(samplerate * x) - 1 | |
157 | x = float(self.options['cnt_overdrive_reset']) / 1000000.0 | |
158 | self.cnt_overdrive_reset = int(samplerate * x) - 1 | |
159 | ||
160 | # Organize values into lists. | |
161 | self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit] | |
162 | self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence] | |
163 | self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset] | |
164 | self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot] | |
165 | ||
166 | # Check if sample times are in the allowed range. | |
167 | ||
168 | time_min = float(self.cnt_normal_bit) / self.samplerate | |
169 | time_max = float(self.cnt_normal_bit + 1) / self.samplerate | |
170 | if (time_min < 0.000005) or (time_max > 0.000015): | |
171 | self.putm([1, ['The normal mode data sample time interval ' + | |
172 | '(%2.1fus-%2.1fus) should be inside (5.0us, 15.0us).' | |
173 | % (time_min * 1000000, time_max * 1000000)]]) | |
174 | ||
175 | time_min = float(self.cnt_normal_presence) / self.samplerate | |
176 | time_max = float(self.cnt_normal_presence + 1) / self.samplerate | |
177 | if (time_min < 0.0000681) or (time_max > 0.000075): | |
178 | self.putm([1, ['The normal mode presence sample time interval ' + | |
179 | '(%2.1fus-%2.1fus) should be inside (68.1us, 75.0us).' | |
180 | % (time_min * 1000000, time_max * 1000000)]]) | |
181 | ||
182 | time_min = float(self.cnt_overdrive_bit) / self.samplerate | |
183 | time_max = float(self.cnt_overdrive_bit + 1) / self.samplerate | |
184 | if (time_min < 0.000001) or (time_max > 0.000002): | |
185 | self.putm([1, ['The overdrive mode data sample time interval ' + | |
186 | '(%2.1fus-%2.1fus) should be inside (1.0us, 2.0us).' | |
187 | % (time_min * 1000000, time_max * 1000000)]]) | |
188 | ||
189 | time_min = float(self.cnt_overdrive_presence) / self.samplerate | |
190 | time_max = float(self.cnt_overdrive_presence + 1) / self.samplerate | |
191 | if (time_min < 0.0000073) or (time_max > 0.000010): | |
192 | self.putm([1, ['The overdrive mode presence sample time interval ' + | |
193 | '(%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).' | |
194 | % (time_min*1000000, time_max*1000000)]]) | |
195 | ||
196 | def decode(self, ss, es, data): | |
197 | if self.samplerate is None: | |
198 | raise Exception("Cannot decode without samplerate.") | |
199 | for (self.samplenum, (owr, pwr)) in data: | |
200 | # State machine. | |
201 | if self.state == 'WAIT FOR FALLING EDGE': | |
202 | # The start of a cycle is a falling edge. | |
203 | if owr != 0: | |
204 | continue | |
205 | # Save the sample number for the falling edge. | |
206 | self.fall = self.samplenum | |
207 | # Go to waiting for sample time. | |
208 | self.state = 'WAIT FOR DATA SAMPLE' | |
209 | elif self.state == 'WAIT FOR DATA SAMPLE': | |
210 | # Sample data bit. | |
211 | t = self.samplenum - self.fall | |
212 | if t == self.cnt_bit[self.overdrive]: | |
213 | self.bit = owr | |
214 | self.state = 'WAIT FOR DATA SLOT END' | |
215 | elif self.state == 'WAIT FOR DATA SLOT END': | |
216 | # A data slot ends in a recovery period, otherwise, this is | |
217 | # probably a reset. | |
218 | t = self.samplenum - self.fall | |
219 | if t != self.cnt_slot[self.overdrive]: | |
220 | continue | |
221 | ||
222 | if owr == 0: | |
223 | # This seems to be a reset slot, wait for its end. | |
224 | self.state = 'WAIT FOR RISING EDGE' | |
225 | continue | |
226 | ||
227 | self.putb([0, ['Bit: %d' % self.bit, '%d' % self.bit]]) | |
228 | self.putpb(['BIT', self.bit]) | |
229 | ||
230 | # Checking the first command to see if overdrive mode | |
231 | # should be entered. | |
232 | if self.bit_cnt <= 8: | |
233 | self.command |= (self.bit << self.bit_cnt) | |
234 | elif self.bit_cnt == 8 and self.command in [0x3c, 0x69]: | |
235 | self.putx([4, ['Entering overdrive mode', 'Overdrive on']]) | |
236 | # Increment the bit counter. | |
237 | self.bit_cnt += 1 | |
238 | # Wait for next slot. | |
239 | self.state = 'WAIT FOR FALLING EDGE' | |
240 | elif self.state == 'WAIT FOR RISING EDGE': | |
241 | # The end of a cycle is a rising edge. | |
242 | if owr != 1: | |
243 | continue | |
244 | ||
245 | # Check if this was a reset cycle. | |
246 | t = self.samplenum - self.fall | |
247 | if t > self.cnt_normal_reset: | |
248 | # Save the sample number for the rising edge. | |
249 | self.rise = self.samplenum | |
250 | self.putfr([2, ['Reset', 'Rst', 'R']]) | |
251 | self.state = 'WAIT FOR PRESENCE DETECT' | |
252 | # Exit overdrive mode. | |
253 | if self.overdrive: | |
254 | self.putx([4, ['Exiting overdrive mode', 'Overdrive off']]) | |
255 | self.overdrive = 0 | |
256 | # Clear command bit counter and data register. | |
257 | self.bit_cnt = 0 | |
258 | self.command = 0 | |
259 | elif (t > self.cnt_overdrive_reset) and self.overdrive: | |
260 | # Save the sample number for the rising edge. | |
261 | self.rise = self.samplenum | |
262 | self.putfr([2, ['Reset', 'Rst', 'R']]) | |
263 | self.state = "WAIT FOR PRESENCE DETECT" | |
264 | # Otherwise this is assumed to be a data bit. | |
265 | else: | |
266 | self.state = "WAIT FOR FALLING EDGE" | |
267 | elif self.state == 'WAIT FOR PRESENCE DETECT': | |
268 | # Sample presence status. | |
269 | t = self.samplenum - self.rise | |
270 | if t == self.cnt_presence[self.overdrive]: | |
271 | self.present = owr | |
272 | self.state = 'WAIT FOR RESET SLOT END' | |
273 | elif self.state == 'WAIT FOR RESET SLOT END': | |
274 | # A reset slot ends in a long recovery period. | |
275 | t = self.samplenum - self.rise | |
276 | if t != self.cnt_reset[self.overdrive]: | |
277 | continue | |
278 | ||
279 | if owr == 0: | |
280 | # This seems to be a reset slot, wait for its end. | |
281 | self.state = 'WAIT FOR RISING EDGE' | |
282 | continue | |
283 | ||
284 | p = 'false' if self.present else 'true' | |
285 | self.putrs([3, ['Presence: %s' % p, 'Presence', 'Pres', 'P']]) | |
286 | self.putprs(['RESET/PRESENCE', not self.present]) | |
287 | ||
288 | # Wait for next slot. | |
289 | self.state = 'WAIT FOR FALLING EDGE' | |
290 | else: | |
291 | raise Exception('Invalid state: %s' % self.state) |