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'},
39 'overdrive': ['Overdrive mode', 'no'],
40 # Time options (specified in microseconds):
41 'cnt_normal_bit': ['Normal mode sample bit time (µs)', 15],
42 'cnt_normal_slot': ['Normal mode data slot time (µs)', 60],
43 'cnt_normal_presence': ['Normal mode sample presence time (µs)', 75],
44 'cnt_normal_reset': ['Normal mode reset time (µs)', 480],
45 'cnt_overdrive_bit': ['Overdrive mode sample bit time (µs)', 2],
46 # 'cnt_overdrive_slot': ['Overdrive mode data slot time (µs)', 7.3],
47 'cnt_overdrive_slot': ['Overdrive mode data slot time (µs)', 7],
48 'cnt_overdrive_presence': ['Overdrive mode sample presence time (µs)', 10],
49 'cnt_overdrive_reset': ['Overdrive mode reset time (µs)', 48],
53 ['warnings', 'Warnings'],
55 ['presence', 'Presence'],
56 ['overdrive', 'Overdrive mode notifications'],
59 ('bits', 'Bits', (0, 2, 3)),
60 ('info', 'Info', (4,)),
61 ('warnings', 'Warnings', (1,)),
65 self.put(0, 0, self.out_ann, data)
67 def putpb(self, data):
68 self.put(self.fall, self.samplenum, self.out_python, data)
71 self.put(self.fall, self.samplenum, self.out_ann, data)
74 self.put(self.fall, self.cnt_bit[self.overdrive], self.out_ann, data)
76 def putfr(self, data):
77 self.put(self.fall, self.rise, self.out_ann, data)
79 def putprs(self, data):
80 self.put(self.rise, self.samplenum, self.out_python, data)
82 def putrs(self, data):
83 self.put(self.rise, self.samplenum, self.out_ann, data)
85 def __init__(self, **kwargs):
86 self.samplerate = None
88 self.state = 'WAIT FOR FALLING EDGE'
98 self.out_python = self.register(srd.OUTPUT_PYTHON)
99 self.out_ann = self.register(srd.OUTPUT_ANN)
101 def metadata(self, key, value):
102 if key != srd.SRD_CONF_SAMPLERATE:
104 self.samplerate = value
106 # Check if samplerate is appropriate.
107 if self.options['overdrive'] == 'yes':
108 if self.samplerate < 2000000:
109 self.putm([1, ['Sampling rate is too low. Must be above ' +
110 '2MHz for proper overdrive mode decoding.']])
111 elif self.samplerate < 5000000:
112 self.putm([1, ['Sampling rate is suggested to be above 5MHz ' +
113 'for proper overdrive mode decoding.']])
115 if self.samplerate < 400000:
116 self.putm([1, ['Sampling rate is too low. Must be above ' +
117 '400kHz for proper normal mode decoding.']])
118 elif (self.samplerate < 1000000):
119 self.putm([1, ['Sampling rate is suggested to be above ' +
120 '1MHz for proper normal mode decoding.']])
122 # The default 1-Wire time base is 30us. This is used to calculate
124 samplerate = float(self.samplerate)
126 x = float(self.options['cnt_normal_bit']) / 1000000.0
127 self.cnt_normal_bit = int(samplerate * x) - 1
128 x = float(self.options['cnt_normal_slot']) / 1000000.0
129 self.cnt_normal_slot = int(samplerate * x) - 1
130 x = float(self.options['cnt_normal_presence']) / 1000000.0
131 self.cnt_normal_presence = int(samplerate * x) - 1
132 x = float(self.options['cnt_normal_reset']) / 1000000.0
133 self.cnt_normal_reset = int(samplerate * x) - 1
134 x = float(self.options['cnt_overdrive_bit']) / 1000000.0
135 self.cnt_overdrive_bit = int(samplerate * x) - 1
136 x = float(self.options['cnt_overdrive_slot']) / 1000000.0
137 self.cnt_overdrive_slot = int(samplerate * x) - 1
138 x = float(self.options['cnt_overdrive_presence']) / 1000000.0
139 self.cnt_overdrive_presence = int(samplerate * x) - 1
140 x = float(self.options['cnt_overdrive_reset']) / 1000000.0
141 self.cnt_overdrive_reset = int(samplerate * x) - 1
143 # Organize values into lists.
144 self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit]
145 self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence]
146 self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset]
147 self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot]
149 # Check if sample times are in the allowed range.
151 time_min = float(self.cnt_normal_bit) / self.samplerate
152 time_max = float(self.cnt_normal_bit + 1) / self.samplerate
153 if (time_min < 0.000005) or (time_max > 0.000015):
154 self.putm([1, ['The normal mode data sample time interval ' +
155 '(%2.1fus-%2.1fus) should be inside (5.0us, 15.0us).'
156 % (time_min * 1000000, time_max * 1000000)]])
158 time_min = float(self.cnt_normal_presence) / self.samplerate
159 time_max = float(self.cnt_normal_presence + 1) / self.samplerate
160 if (time_min < 0.0000681) or (time_max > 0.000075):
161 self.putm([1, ['The normal mode presence sample time interval ' +
162 '(%2.1fus-%2.1fus) should be inside (68.1us, 75.0us).'
163 % (time_min * 1000000, time_max * 1000000)]])
165 time_min = float(self.cnt_overdrive_bit) / self.samplerate
166 time_max = float(self.cnt_overdrive_bit + 1) / self.samplerate
167 if (time_min < 0.000001) or (time_max > 0.000002):
168 self.putm([1, ['The overdrive mode data sample time interval ' +
169 '(%2.1fus-%2.1fus) should be inside (1.0us, 2.0us).'
170 % (time_min * 1000000, time_max * 1000000)]])
172 time_min = float(self.cnt_overdrive_presence) / self.samplerate
173 time_max = float(self.cnt_overdrive_presence + 1) / self.samplerate
174 if (time_min < 0.0000073) or (time_max > 0.000010):
175 self.putm([1, ['The overdrive mode presence sample time interval ' +
176 '(%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).'
177 % (time_min*1000000, time_max*1000000)]])
179 def decode(self, ss, es, data):
180 if self.samplerate is None:
181 raise Exception("Cannot decode without samplerate.")
182 for (self.samplenum, (owr, pwr)) in data:
184 if self.state == 'WAIT FOR FALLING EDGE':
185 # The start of a cycle is a falling edge.
188 # Save the sample number for the falling edge.
189 self.fall = self.samplenum
190 # Go to waiting for sample time.
191 self.state = 'WAIT FOR DATA SAMPLE'
192 elif self.state == 'WAIT FOR DATA SAMPLE':
194 t = self.samplenum - self.fall
195 if t == self.cnt_bit[self.overdrive]:
197 self.state = 'WAIT FOR DATA SLOT END'
198 elif self.state == 'WAIT FOR DATA SLOT END':
199 # A data slot ends in a recovery period, otherwise, this is
201 t = self.samplenum - self.fall
202 if t != self.cnt_slot[self.overdrive]:
206 # This seems to be a reset slot, wait for its end.
207 self.state = 'WAIT FOR RISING EDGE'
210 self.putb([0, ['Bit: %d' % self.bit, '%d' % self.bit]])
211 self.putpb(['BIT', self.bit])
213 # Checking the first command to see if overdrive mode
215 if self.bit_cnt <= 8:
216 self.command |= (self.bit << self.bit_cnt)
217 elif self.bit_cnt == 8 and self.command in [0x3c, 0x69]:
218 self.putx([4, ['Entering overdrive mode', 'Overdrive on']])
219 # Increment the bit counter.
221 # Wait for next slot.
222 self.state = 'WAIT FOR FALLING EDGE'
223 elif self.state == 'WAIT FOR RISING EDGE':
224 # The end of a cycle is a rising edge.
228 # Check if this was a reset cycle.
229 t = self.samplenum - self.fall
230 if t > self.cnt_normal_reset:
231 # Save the sample number for the rising edge.
232 self.rise = self.samplenum
233 self.putfr([2, ['Reset', 'Rst', 'R']])
234 self.state = 'WAIT FOR PRESENCE DETECT'
235 # Exit overdrive mode.
237 self.putx([4, ['Exiting overdrive mode', 'Overdrive off']])
239 # Clear command bit counter and data register.
242 elif (t > self.cnt_overdrive_reset) and self.overdrive:
243 # Save the sample number for the rising edge.
244 self.rise = self.samplenum
245 self.putfr([2, ['Reset', 'Rst', 'R']])
246 self.state = "WAIT FOR PRESENCE DETECT"
247 # Otherwise this is assumed to be a data bit.
249 self.state = "WAIT FOR FALLING EDGE"
250 elif self.state == 'WAIT FOR PRESENCE DETECT':
251 # Sample presence status.
252 t = self.samplenum - self.rise
253 if t == self.cnt_presence[self.overdrive]:
255 self.state = 'WAIT FOR RESET SLOT END'
256 elif self.state == 'WAIT FOR RESET SLOT END':
257 # A reset slot ends in a long recovery period.
258 t = self.samplenum - self.rise
259 if t != self.cnt_reset[self.overdrive]:
263 # This seems to be a reset slot, wait for its end.
264 self.state = 'WAIT FOR RISING EDGE'
267 p = 'false' if self.present else 'true'
268 self.putrs([3, ['Presence: %s' % p, 'Presence', 'Pres', 'P']])
269 self.putprs(['RESET/PRESENCE', not self.present])
271 # Wait for next slot.
272 self.state = 'WAIT FOR FALLING EDGE'
274 raise Exception('Invalid state: %s' % self.state)