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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 | channels = ( | |
33 | {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire signal line'}, | |
34 | ) | |
35 | optional_channels = ( | |
36 | {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power supply pin'}, | |
37 | ) | |
38 | options = ( | |
39 | {'id': 'overdrive', | |
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}, | |
58 | ) | |
59 | annotations = ( | |
60 | ('bit', 'Bit'), | |
61 | ('warnings', 'Warnings'), | |
62 | ('reset', 'Reset'), | |
63 | ('presence', 'Presence'), | |
64 | ('overdrive', 'Overdrive mode notifications'), | |
65 | ) | |
66 | annotation_rows = ( | |
67 | ('bits', 'Bits', (0, 2, 3)), | |
68 | ('info', 'Info', (4,)), | |
69 | ('warnings', 'Warnings', (1,)), | |
70 | ) | |
71 | ||
72 | def putm(self, data): | |
73 | self.put(0, 0, self.out_ann, data) | |
74 | ||
75 | def putpb(self, data): | |
76 | self.put(self.fall, self.samplenum, self.out_python, data) | |
77 | ||
78 | def putb(self, data): | |
79 | self.put(self.fall, self.samplenum, self.out_ann, data) | |
80 | ||
81 | def putx(self, data): | |
82 | self.put(self.fall, self.cnt_bit[self.overdrive], self.out_ann, data) | |
83 | ||
84 | def putfr(self, data): | |
85 | self.put(self.fall, self.rise, self.out_ann, data) | |
86 | ||
87 | def putprs(self, data): | |
88 | self.put(self.rise, self.samplenum, self.out_python, data) | |
89 | ||
90 | def putrs(self, data): | |
91 | self.put(self.rise, self.samplenum, self.out_ann, data) | |
92 | ||
93 | def __init__(self, **kwargs): | |
94 | self.samplerate = None | |
95 | self.samplenum = 0 | |
96 | self.state = 'WAIT FOR FALLING EDGE' | |
97 | self.present = 0 | |
98 | self.bit = 0 | |
99 | self.bit_cnt = 0 | |
100 | self.command = 0 | |
101 | self.overdrive = 0 | |
102 | self.fall = 0 | |
103 | self.rise = 0 | |
104 | ||
105 | def start(self): | |
106 | self.out_python = self.register(srd.OUTPUT_PYTHON) | |
107 | self.out_ann = self.register(srd.OUTPUT_ANN) | |
108 | ||
109 | def metadata(self, key, value): | |
110 | if key != srd.SRD_CONF_SAMPLERATE: | |
111 | return | |
112 | self.samplerate = value | |
113 | ||
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.']]) | |
122 | else: | |
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.']]) | |
129 | ||
130 | # The default 1-Wire time base is 30us. This is used to calculate | |
131 | # sampling times. | |
132 | samplerate = float(self.samplerate) | |
133 | ||
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 | |
150 | ||
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] | |
156 | ||
157 | # Check if sample times are in the allowed range. | |
158 | ||
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)]]) | |
165 | ||
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)]]) | |
172 | ||
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)]]) | |
179 | ||
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)]]) | |
186 | ||
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: | |
191 | # State machine. | |
192 | if self.state == 'WAIT FOR FALLING EDGE': | |
193 | # The start of a cycle is a falling edge. | |
194 | if owr != 0: | |
195 | continue | |
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': | |
201 | # Sample data bit. | |
202 | t = self.samplenum - self.fall | |
203 | if t == self.cnt_bit[self.overdrive]: | |
204 | self.bit = owr | |
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 | |
208 | # probably a reset. | |
209 | t = self.samplenum - self.fall | |
210 | if t != self.cnt_slot[self.overdrive]: | |
211 | continue | |
212 | ||
213 | if owr == 0: | |
214 | # This seems to be a reset slot, wait for its end. | |
215 | self.state = 'WAIT FOR RISING EDGE' | |
216 | continue | |
217 | ||
218 | self.putb([0, ['Bit: %d' % self.bit, '%d' % self.bit]]) | |
219 | self.putpb(['BIT', self.bit]) | |
220 | ||
221 | # Checking the first command to see if overdrive mode | |
222 | # should be entered. | |
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. | |
228 | self.bit_cnt += 1 | |
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. | |
233 | if owr != 1: | |
234 | continue | |
235 | ||
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. | |
244 | if self.overdrive: | |
245 | self.putx([4, ['Exiting overdrive mode', 'Overdrive off']]) | |
246 | self.overdrive = 0 | |
247 | # Clear command bit counter and data register. | |
248 | self.bit_cnt = 0 | |
249 | self.command = 0 | |
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. | |
256 | else: | |
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]: | |
262 | self.present = owr | |
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]: | |
268 | continue | |
269 | ||
270 | if owr == 0: | |
271 | # This seems to be a reset slot, wait for its end. | |
272 | self.state = 'WAIT FOR RISING EDGE' | |
273 | continue | |
274 | ||
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]) | |
278 | ||
279 | # Wait for next slot. | |
280 | self.state = 'WAIT FOR FALLING EDGE' | |
281 | else: | |
282 | raise Exception('Invalid state: %s' % self.state) |