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added some ducumentation, shortened the ROM command decoder code
[libsigrokdecode.git] / decoders / onewire / onewire.py
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1##
2## This file is part of the sigrok project.
3##
4## Copyright (C) 2011-2012 Uwe Hermann <uwe@hermann-uwe.de>
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# 1-Wire protocol decoder
22
23import sigrokdecode as srd
24
25# Annotation feed formats
26ANN_LINK = 0
27ANN_NETWORK = 1
28ANN_TRANSPORT = 2
29
30# a dictionary of ROM commands and their names
31rom_command = {0x33: "READ ROM",
32 0x0f: "CONDITIONAL READ ROM",
33 0xcc: "SKIP ROM",
34 0x55: "MATCH ROM",
35 0xf0: "SEARCH ROM",
36 0xec: "CONDITIONAL SEARCH ROM",
37 0x3c: "OVERDRIVE SKIP ROM",
38 0x6d: "OVERDRIVE MATCH ROM"}
39
40class Decoder(srd.Decoder):
41 api_version = 1
42 id = 'onewire'
43 name = '1-Wire'
44 longname = ''
45 desc = '1-Wire bus and MicroLan'
46 license = 'gplv2+'
47 inputs = ['logic']
48 outputs = ['onewire']
49 probes = [
50 {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire bus'},
51 ]
52 optional_probes = [
53 {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power'},
54 ]
55 options = {
56 'overdrive' : ['Overdrive', 1],
57 'cnt_normal_bit' : ['Time (in samplerate periods) for normal mode sample bit' , 0],
58 'cnt_normal_presence' : ['Time (in samplerate periods) for normal mode sample presence', 0],
59 'cnt_normal_reset' : ['Time (in samplerate periods) for normal mode reset' , 0],
60 'cnt_overdrive_bit' : ['Time (in samplerate periods) for overdrive mode sample bit' , 0],
61 'cnt_overdrive_presence': ['Time (in samplerate periods) for overdrive mode sample presence', 0],
62 'cnt_overdrive_reset' : ['Time (in samplerate periods) for overdrive mode reset' , 0],
63 }
64 annotations = [
65 ['Link', 'Link layer events (reset, presence, bit slots)'],
66 ['Network', 'Network layer events (device addressing)'],
67 ['Transport', 'Transport layer events'],
68 ]
69
70 def __init__(self, **kwargs):
71 # Common variables
72 self.samplenum = 0
73 # Link layer variables
74 self.lnk_state = 'WAIT FOR FALLING EDGE'
75 self.lnk_event = 'NONE'
76 self.lnk_present = 0
77 self.lnk_bit = 0
78 self.lnk_overdrive = 0
79 # Event timing variables
80 self.lnk_fall = 0
81 self.lnk_rise = 0
82 self.net_beg = 0
83 self.net_end = 0
84 # Network layer variables
85 self.net_state = 'IDLE'
86 self.net_cnt = 0
87 self.net_search = "P"
88 self.net_data_p = 0x0
89 self.net_data_n = 0x0
90 self.net_data = 0x0
91 self.net_rom = 0x0000000000000000
92
93 def start(self, metadata):
94 self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire')
95 self.out_ann = self.add(srd.OUTPUT_ANN , 'onewire')
96
97 # check if samplerate is appropriate
98 self.samplerate = metadata['samplerate']
99 if (self.options['overdrive']):
100 self.put(0, 0, self.out_ann, [ANN_LINK, ['NOTE: Sample rate checks assume overdrive mode.']])
101 if (self.samplerate < 2000000):
102 self.put(0, 0, self.out_ann, [ANN_LINK, ['ERROR: Sampling rate is too low must be above 2MHz for proper overdrive mode decoding.']])
103 elif (self.samplerate < 5000000):
104 self.put(0, 0, self.out_ann, [ANN_LINK, ['WARNING: Sampling rate is suggested to be above 5MHz for proper overdrive mode decoding.']])
105 else:
106 self.put(0, 0, self.out_ann, [ANN_LINK, ['NOTE: Sample rate checks assume normal mode only.']])
107 if (self.samplerate < 400000):
108 self.put(0, 0, self.out_ann, [ANN_LINK, ['ERROR: Sampling rate is too low must be above 400kHz for proper normal mode decoding.']])
109 elif (self.samplerate < 1000000):
110 self.put(0, 0, self.out_ann, [ANN_LINK, ['WARNING: Sampling rate is suggested to be above 1MHz for proper normal mode decoding.']])
111
112 # The default 1-Wire time base is 30us, this is used to calculate sampling times.
113 if (self.options['cnt_normal_bit']): self.cnt_normal_bit = self.options['cnt_normal_bit']
114 else: self.cnt_normal_bit = int(float(self.samplerate) * 0.000015) - 1 # 15ns
115 if (self.options['cnt_normal_presence']): self.cnt_normal_presence = self.options['cnt_normal_presence']
116 else: self.cnt_normal_presence = int(float(self.samplerate) * 0.000075) - 1 # 75ns
117 if (self.options['cnt_normal_reset']): self.cnt_normal_reset = self.options['cnt_normal_reset']
118 else: self.cnt_normal_reset = int(float(self.samplerate) * 0.000480) - 1 # 480ns
119 if (self.options['cnt_overdrive_bit']): self.cnt_overdrive_bit = self.options['cnt_overdrive_bit']
120 else: self.cnt_overdrive_bit = int(float(self.samplerate) * 0.000002) - 1 # 2ns
121 if (self.options['cnt_overdrive_presence']): self.cnt_overdrive_presence = self.options['cnt_overdrive_presence']
122 else: self.cnt_overdrive_presence = int(float(self.samplerate) * 0.000010) - 1 # 10ns
123 if (self.options['cnt_overdrive_reset']): self.cnt_overdrive_reset = self.options['cnt_overdrive_reset']
124 else: self.cnt_overdrive_reset = int(float(self.samplerate) * 0.000048) - 1 # 48ns
125
126 # Check if sample times are in the allowed range
127 time_min = float(self.cnt_normal_bit ) / self.samplerate
128 time_max = float(self.cnt_normal_bit+1) / self.samplerate
129 if ( (time_min < 0.000005) or (time_max > 0.000015) ) :
130 self.put(0, 0, self.out_ann, [ANN_LINK, ['WARNING: The normal mode data sample time interval (%2.1fus-%2.1fus) should be inside (5.0us, 15.0us).' % (time_min*1000000, time_max*1000000)]])
131 time_min = float(self.cnt_normal_presence ) / self.samplerate
132 time_max = float(self.cnt_normal_presence+1) / self.samplerate
133 if ( (time_min < 0.0000681) or (time_max > 0.000075) ) :
134 self.put(0, 0, self.out_ann, [ANN_LINK, ['WARNING: The normal mode presence sample time interval (%2.1fus-%2.1fus) should be inside (68.1us, 75.0us).' % (time_min*1000000, time_max*1000000)]])
135 time_min = float(self.cnt_overdrive_bit ) / self.samplerate
136 time_max = float(self.cnt_overdrive_bit+1) / self.samplerate
137 if ( (time_min < 0.000001) or (time_max > 0.000002) ) :
138 self.put(0, 0, self.out_ann, [ANN_LINK, ['WARNING: The overdrive mode data sample time interval (%2.1fus-%2.1fus) should be inside (1.0us, 2.0us).' % (time_min*1000000, time_max*1000000)]])
139 time_min = float(self.cnt_overdrive_presence ) / self.samplerate
140 time_max = float(self.cnt_overdrive_presence+1) / self.samplerate
141 if ( (time_min < 0.0000073) or (time_max > 0.000010) ) :
142 self.put(0, 0, self.out_ann, [ANN_LINK, ['WARNING: The overdrive mode presence sample time interval (%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).' % (time_min*1000000, time_max*1000000)]])
143
144 def report(self):
145 pass
146
147 def decode(self, ss, es, data):
148 for (self.samplenum, (owr, pwr)) in data:
149
150 # Data link layer
151
152 # Clear events.
153 self.lnk_event = "NONE"
154 # State machine.
155 if self.lnk_state == 'WAIT FOR FALLING EDGE':
156 # The start of a cycle is a falling edge.
157 if (owr == 0):
158 # Save the sample number for the falling edge.
159 self.lnk_fall = self.samplenum
160 # Go to waiting for sample time
161 self.lnk_state = 'WAIT FOR DATA SAMPLE'
162 elif self.lnk_state == 'WAIT FOR DATA SAMPLE':
163 # Sample data bit
164 if (self.lnk_overdrive): cnt = self.cnt_overdrive_bit
165 else : cnt = self.cnt_normal_bit
166 if (self.samplenum - self.lnk_fall == cnt):
167 self.lnk_bit = owr & 0x1
168 self.lnk_event = "DATA BIT"
169 if (self.lnk_bit): self.lnk_state = 'WAIT FOR FALLING EDGE'
170 else : self.lnk_state = 'WAIT FOR RISING EDGE'
171 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_LINK, ['BIT: %01x' % self.lnk_bit]])
172 elif self.lnk_state == 'WAIT FOR RISING EDGE':
173 # The end of a cycle is a rising edge.
174 if (owr == 1):
175 # Check if this was a reset cycle
176 if (self.samplenum - self.lnk_fall > self.cnt_normal_reset):
177 # Save the sample number for the falling edge.
178 self.lnk_rise = self.samplenum
179 # Send a reset event to the next protocol layer.
180 self.lnk_event = "RESET"
181 self.lnk_state = "WAIT FOR PRESENCE DETECT"
182 self.put(self.lnk_fall, self.samplenum, self.out_proto, ['RESET'])
183 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_LINK , ['RESET']])
184 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_NETWORK , ['RESET']])
185 # Reset the timer.
186 self.lnk_fall = self.samplenum
187 elif ((self.samplenum - self.lnk_fall > self.cnt_overdrive_reset) and (self.lnk_overdrive)):
188 # Save the sample number for the falling edge.
189 self.lnk_rise = self.samplenum
190 # Send a reset event to the next protocol layer.
191 self.lnk_event = "RESET"
192 self.lnk_state = "WAIT FOR PRESENCE DETECT"
193 self.put(self.lnk_fall, self.samplenum, self.out_proto, ['RESET OVERDRIVE'])
194 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_LINK , ['RESET OVERDRIVE']])
195 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_NETWORK , ['RESET OVERDRIVE']])
196 # Reset the timer.
197 self.lnk_fall = self.samplenum
198 # Otherwise this is assumed to be a data bit.
199 else :
200 self.lnk_state = "WAIT FOR FALLING EDGE"
201 elif self.lnk_state == 'WAIT FOR PRESENCE DETECT':
202 # Sample presence status
203 if (self.lnk_overdrive): cnt = self.cnt_overdrive_presence
204 else : cnt = self.cnt_normal_presence
205 if (self.samplenum - self.lnk_rise == cnt):
206 self.lnk_present = owr & 0x1
207 # Save the sample number for the falling edge.
208 if not (self.lnk_present) : self.lnk_fall = self.samplenum
209 # create presence detect event
210 #self.lnk_event = "PRESENCE DETECT"
211 if (self.lnk_present) : self.lnk_state = 'WAIT FOR FALLING EDGE'
212 else : self.lnk_state = 'WAIT FOR RISING EDGE'
213 present_str = "False" if self.lnk_present else "True"
214 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_LINK , ['PRESENCE: ' + present_str]])
215 self.put(self.lnk_fall, self.samplenum, self.out_ann, [ANN_NETWORK, ['PRESENCE: ' + present_str]])
216 else:
217 raise Exception('Invalid lnk_state: %d' % self.lnk_state)
218
219 # Network layer
220
221 # State machine.
222 if (self.lnk_event == "RESET"):
223 self.net_state = "COMMAND"
224 self.net_search = "P"
225 self.net_cnt = 0
226 elif (self.net_state == "IDLE"):
227 pass
228 elif (self.net_state == "COMMAND"):
229 # Receiving and decoding a ROM command
230 if (self.onewire_collect(8)):
231 self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM COMMAND: 0x%02x \'%s\'' % (self.net_data, rom_command[self.net_data])]])
232 if (self.net_data == 0x33): # READ ROM
233 self.net_state = "GET ROM"
234 elif (self.net_data == 0x0f): # CONDITIONAL READ ROM
235 self.net_state = "GET ROM"
236 elif (self.net_data == 0xcc): # SKIP ROM
237 self.net_state = "TRANSPORT"
238 elif (self.net_data == 0x55): # MATCH ROM
239 self.net_state = "GET ROM"
240 elif (self.net_data == 0xf0): # SEARCH ROM
241 self.net_state = "SEARCH ROM"
242 elif (self.net_data == 0xec): # CONDITIONAL SEARCH ROM
243 self.net_state = "SEARCH ROM"
244 elif (self.net_data == 0x3c): # OVERDRIVE SKIP ROM
245 self.lnk_overdrive = 1
246 self.net_state = "TRANSPORT"
247 elif (self.net_data == 0x69): # OVERDRIVE MATCH ROM
248 self.lnk_overdrive = 1
249 self.net_state = "GET ROM"
250 elif (self.net_state == "GET ROM"):
251 # A 64 bit device address is selected
252 # family code (1B) + serial number (6B) + CRC (1B)
253 if (self.onewire_collect(64)):
254 self.net_rom = self.net_data & 0xffffffffffffffff
255 self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]])
256 self.net_state = "TRANSPORT"
257 elif (self.net_state == "SEARCH ROM"):
258 # A 64 bit device address is searched for
259 # family code (1B) + serial number (6B) + CRC (1B)
260 if (self.onewire_search(64)):
261 self.net_rom = self.net_data & 0xffffffffffffffff
262 self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]])
263 self.net_state = "TRANSPORT"
264 elif (self.net_state == "TRANSPORT"):
265 # The transport layer is handled in byte sized units
266 if (self.onewire_collect(8)):
267 self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK , ['TRANSPORT: 0x%02x' % self.net_data]])
268 self.put(self.net_beg, self.net_end, self.out_ann, [ANN_TRANSPORT, ['TRANSPORT: 0x%02x' % self.net_data]])
269 self.put(self.net_beg, self.net_end, self.out_proto, ['transfer', self.net_data])
270 # TODO: Sending translort layer data to 1-Wire device models
271 else:
272 raise Exception('Invalid net_state: %s' % self.net_state)
273
274
275 # Link/Network layer data collector
276 def onewire_collect (self, length):
277 if (self.lnk_event == "DATA BIT"):
278 # Storing the sampe this sequence begins with
279 if (self.net_cnt == 1):
280 self.net_beg = self.samplenum
281 self.net_data = self.net_data & ~(1 << self.net_cnt) | (self.lnk_bit << self.net_cnt)
282 self.net_cnt = self.net_cnt + 1
283 # Storing the sampe this sequence ends with
284 # In case the full length of the sequence is received, return 1
285 if (self.net_cnt == length):
286 self.net_end = self.samplenum
287 self.net_data = self.net_data & ((1<<length)-1)
288 self.net_cnt = 0
289 return (1)
290 else:
291 return (0)
292 else:
293 return (0)
294
295 # Link/Network layer search collector
296 def onewire_search (self, length):
297 if (self.lnk_event == "DATA BIT"):
298 # Storing the sampe this sequence begins with
299 if ((self.net_cnt == 0) and (self.net_search == "P")):
300 self.net_beg = self.samplenum
301 # Master receives an original address bit
302 if (self.net_search == "P"):
303 self.net_data_p = self.net_data_p & ~(1 << self.net_cnt) | (self.lnk_bit << self.net_cnt)
304 self.net_search = "N"
305 # Master receives a complemented address bit
306 elif (self.net_search == "N"):
307 self.net_data_n = self.net_data_n & ~(1 << self.net_cnt) | (self.lnk_bit << self.net_cnt)
308 self.net_search = "D"
309 # Master transmits an address bit
310 elif (self.net_search == "D"):
311 self.net_data = self.net_data & ~(1 << self.net_cnt) | (self.lnk_bit << self.net_cnt)
312 self.net_search = "P"
313 self.net_cnt = self.net_cnt + 1
314 # Storing the sampe this sequence ends with
315 # In case the full length of the sequence is received, return 1
316 if (self.net_cnt == length):
317 self.net_end = self.samplenum
318 self.net_data_p = self.net_data_p & ((1<<length)-1)
319 self.net_data_n = self.net_data_n & ((1<<length)-1)
320 self.net_data = self.net_data & ((1<<length)-1)
321 self.net_search = "P"
322 self.net_cnt = 0
323 return (1)
324 else:
325 return (0)
326 else:
327 return (0)
Protocol decoder lib