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1 | ## | |
2 | ## This file is part of the libsigrokdecode project. | |
3 | ## | |
4 | ## Copyright (C) 2015 Benjamin Larsson <benjamin@southpole.se> | |
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 SamplerateError(Exception): | |
24 | pass | |
25 | ||
26 | class Decoder(srd.Decoder): | |
27 | api_version = 2 | |
28 | id = 'em4100' | |
29 | name = 'EM4100' | |
30 | longname = 'RFID EM4100' | |
31 | desc = 'EM4100 100-150kHz RFID protocol.' | |
32 | license = 'gplv2+' | |
33 | inputs = ['logic'] | |
34 | outputs = ['em4100'] | |
35 | channels = ( | |
36 | {'id': 'data', 'name': 'Data', 'desc': 'Data line'}, | |
37 | ) | |
38 | options = ( | |
39 | {'id': 'polarity', 'desc': 'Polarity', 'default': 'active-high', | |
40 | 'values': ('active-low', 'active-high')}, | |
41 | {'id': 'datarate' , 'desc': 'Data rate', 'default': 64, | |
42 | 'values': (64, 32, 16)}, | |
43 | # {'id': 'coding', 'desc': 'Bit coding', 'default': 'biphase', | |
44 | # 'values': ('biphase', 'manchester', 'psk')}, | |
45 | {'id': 'coilfreq', 'desc': 'Coil frequency', 'default': 125000}, | |
46 | ) | |
47 | annotations = ( | |
48 | ('bit', 'Bit'), | |
49 | ('header', 'Header'), | |
50 | ('version-customer', 'Version/customer'), | |
51 | ('data', 'Data'), | |
52 | ('rowparity-ok', 'Row parity OK'), | |
53 | ('rowparity-err', 'Row parity error'), | |
54 | ('colparity-ok', 'Column parity OK'), | |
55 | ('colparity-err', 'Column parity error'), | |
56 | ('stopbit', 'Stop bit'), | |
57 | ('tag', 'Tag'), | |
58 | ) | |
59 | annotation_rows = ( | |
60 | ('bits', 'Bits', (0,)), | |
61 | ('fields', 'Fields', (1, 2, 3, 4, 5, 6, 7, 8)), | |
62 | ('tags', 'Tags', (9,)), | |
63 | ) | |
64 | ||
65 | def __init__(self, **kwargs): | |
66 | self.samplerate = None | |
67 | self.oldpin = None | |
68 | self.last_samplenum = None | |
69 | self.lastlast_samplenum = None | |
70 | self.last_edge = 0 | |
71 | self.bit_width = 0 | |
72 | self.halfbit_limit = 0 | |
73 | self.oldpp = 0 | |
74 | self.oldpl = 0 | |
75 | self.oldsamplenum = 0 | |
76 | self.last_bit_pos = 0 | |
77 | self.first_ss = 0 | |
78 | self.first_one = 0 | |
79 | self.state = 'HEADER' | |
80 | self.data = 0 | |
81 | self.data_bits = 0 | |
82 | self.data_ss = 0 | |
83 | self.data_parity = 0 | |
84 | self.payload_cnt = 0 | |
85 | self.data_col_parity = [0, 0, 0, 0, 0, 0] | |
86 | self.col_parity = [0, 0, 0, 0, 0, 0] | |
87 | self.tag = 0 | |
88 | self.all_row_parity_ok = True | |
89 | self.col_parity_pos = [] | |
90 | ||
91 | def metadata(self, key, value): | |
92 | if key == srd.SRD_CONF_SAMPLERATE: | |
93 | self.samplerate = value | |
94 | self.bit_width = (self.samplerate / self.options['coilfreq']) * self.options['datarate'] | |
95 | self.halfbit_limit = self.bit_width/2 + self.bit_width/4 | |
96 | self.polarity = 0 if self.options['polarity'] == 'active-low' else 1 | |
97 | ||
98 | def start(self): | |
99 | self.out_ann = self.register(srd.OUTPUT_ANN) | |
100 | ||
101 | def putbit(self, bit, ss, es): | |
102 | self.put(ss, es, self.out_ann, [0, [str(bit)]]) | |
103 | if self.state == 'HEADER': | |
104 | if bit == 1: | |
105 | if self.first_one > 0: | |
106 | self.first_one += 1 | |
107 | if self.first_one == 9: | |
108 | self.put(self.first_ss, es, self.out_ann, | |
109 | [1, ['Header', 'Head', 'He', 'H']]) | |
110 | self.first_one = 0 | |
111 | self.state = 'PAYLOAD' | |
112 | return | |
113 | if self.first_one == 0: | |
114 | self.first_one = 1 | |
115 | self.first_ss = ss | |
116 | ||
117 | if bit == 0: | |
118 | self.first_one = 0 | |
119 | return | |
120 | ||
121 | if self.state == 'PAYLOAD': | |
122 | self.payload_cnt += 1 | |
123 | if self.data_bits == 0: | |
124 | self.data_ss = ss | |
125 | self.data = 0 | |
126 | self.data_parity = 0 | |
127 | self.data_bits += 1 | |
128 | if self.data_bits == 5: | |
129 | s = 'Version/customer' if self.payload_cnt <= 10 else 'Data' | |
130 | c = 2 if self.payload_cnt <= 10 else 3 | |
131 | self.put(self.data_ss, ss, self.out_ann, | |
132 | [c, [s + ': %X' % self.data, '%X' % self.data]]) | |
133 | s = 'OK' if self.data_parity == bit else 'ERROR' | |
134 | c = 4 if s == 'OK' else 5 | |
135 | if s == 'ERROR': | |
136 | self.all_row_parity_ok = False | |
137 | self.put(ss, es, self.out_ann, | |
138 | [c, ['Row parity: ' + s, 'RP: ' + s, 'RP', 'R']]) | |
139 | self.tag = (self.tag << 4) | self.data | |
140 | self.data_bits = 0 | |
141 | if self.payload_cnt == 50: | |
142 | self.state = 'TRAILER' | |
143 | self.payload_cnt = 0 | |
144 | ||
145 | self.data_parity ^= bit | |
146 | self.data_col_parity[self.data_bits] ^= bit | |
147 | self.data = (self.data << 1) | bit | |
148 | return | |
149 | ||
150 | if self.state == 'TRAILER': | |
151 | self.payload_cnt += 1 | |
152 | if self.data_bits == 0: | |
153 | self.data_ss = ss | |
154 | self.data = 0 | |
155 | self.data_parity = 0 | |
156 | self.data_bits += 1 | |
157 | self.col_parity[self.data_bits] = bit | |
158 | self.col_parity_pos.append([ss, es]) | |
159 | ||
160 | if self.data_bits == 5: | |
161 | self.put(ss, es, self.out_ann, [8, ['Stop bit', 'SB', 'S']]) | |
162 | ||
163 | for i in range(1, 5): | |
164 | s = 'OK' if self.data_col_parity[i] == \ | |
165 | self.col_parity[i] else 'ERROR' | |
166 | c = 6 if s == 'OK' else 7 | |
167 | self.put(self.col_parity_pos[i - 1][0], | |
168 | self.col_parity_pos[i - 1][1], self.out_ann, | |
169 | [c, ['Column parity %d: %s' % (i, s), | |
170 | 'CP%d: %s' % (i, s), 'CP%d' % i, 'C']]) | |
171 | ||
172 | # Emit an annotation for valid-looking tags. | |
173 | all_col_parity_ok = (self.data_col_parity[1:5] == self.col_parity[1:5]) | |
174 | if all_col_parity_ok and self.all_row_parity_ok: | |
175 | self.put(self.first_ss, es, self.out_ann, | |
176 | [9, ['Tag: %010X' % self.tag, 'Tag', 'T']]) | |
177 | ||
178 | self.tag = 0 | |
179 | self.data_bits = 0 | |
180 | ||
181 | if self.payload_cnt == 5: | |
182 | self.state = 'HEADER' | |
183 | self.payload_cnt = 0 | |
184 | self.data_col_parity = [0, 0, 0, 0, 0, 0] | |
185 | self.col_parity = [0, 0, 0, 0, 0, 0] | |
186 | self.col_parity_pos = [] | |
187 | self.all_row_parity_ok = True | |
188 | ||
189 | def manchester_decode(self, samplenum, pl, pp, pin): | |
190 | bit = self.oldpin ^ self.polarity | |
191 | if pl > self.halfbit_limit: | |
192 | es = int(samplenum - pl/2) | |
193 | if self.oldpl > self.halfbit_limit: | |
194 | ss = int(self.oldsamplenum - self.oldpl/2) | |
195 | else: | |
196 | ss = int(self.oldsamplenum - self.oldpl) | |
197 | self.putbit(bit, ss, es) | |
198 | self.last_bit_pos = int(samplenum - pl/2) | |
199 | else: | |
200 | es = int(samplenum) | |
201 | if self.oldpl > self.halfbit_limit: | |
202 | ss = int(self.oldsamplenum - self.oldpl/2) | |
203 | self.putbit(bit, ss, es) | |
204 | self.last_bit_pos = int(samplenum) | |
205 | else: | |
206 | if self.last_bit_pos <= self.oldsamplenum - self.oldpl: | |
207 | ss = int(self.oldsamplenum - self.oldpl) | |
208 | self.putbit(bit, ss, es) | |
209 | self.last_bit_pos = int(samplenum) | |
210 | ||
211 | def decode(self, ss, es, data): | |
212 | if not self.samplerate: | |
213 | raise SamplerateError('Cannot decode without samplerate.') | |
214 | for (samplenum, (pin,)) in data: | |
215 | # Ignore identical samples early on (for performance reasons). | |
216 | if self.oldpin == pin: | |
217 | continue | |
218 | ||
219 | if self.oldpin is None: | |
220 | self.oldpin = pin | |
221 | self.last_samplenum = samplenum | |
222 | self.lastlast_samplenum = samplenum | |
223 | self.last_edge = samplenum | |
224 | self.oldpl = 0 | |
225 | self.oldpp = 0 | |
226 | self.oldsamplenum = 0 | |
227 | self.last_bit_pos = 0 | |
228 | continue | |
229 | ||
230 | if self.oldpin != pin: | |
231 | pl = samplenum - self.oldsamplenum | |
232 | pp = pin | |
233 | self.manchester_decode(samplenum, pl, pp, pin) | |
234 | self.oldpl = pl | |
235 | self.oldpp = pp | |
236 | self.oldsamplenum = samplenum | |
237 | self.oldpin = pin |