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6eb87578 GM |
1 | ## |
2 | ## This file is part of the sigrok project. | |
3 | ## | |
4 | ## Copyright (C) 2011 Gareth McMullin <gareth@blacksphere.co.nz> | |
d6bace96 | 5 | ## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de> |
6eb87578 GM |
6 | ## |
7 | ## This program is free software; you can redistribute it and/or modify | |
8 | ## it under the terms of the GNU General Public License as published by | |
9 | ## the Free Software Foundation; either version 2 of the License, or | |
10 | ## (at your option) any later version. | |
11 | ## | |
12 | ## This program is distributed in the hope that it will be useful, | |
13 | ## but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | ## GNU General Public License for more details. | |
16 | ## | |
17 | ## You should have received a copy of the GNU General Public License | |
18 | ## along with this program; if not, write to the Free Software | |
19 | ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | ## | |
ad2dc0de | 21 | |
677d597b | 22 | import sigrokdecode as srd |
67e847fd | 23 | |
238b4080 UH |
24 | # Chip-select options |
25 | ACTIVE_LOW = 0 | |
26 | ACTIVE_HIGH = 1 | |
27 | ||
28 | # Clock polarity options | |
29 | CPOL_0 = 0 # Clock is low when inactive | |
30 | CPOL_1 = 1 # Clock is high when inactive | |
31 | ||
32 | # Clock phase options | |
33 | CPHA_0 = 0 # Data is valid on the rising clock edge | |
34 | CPHA_1 = 1 # Data is valid on the falling clock edge | |
35 | ||
36 | # Bit order options | |
37 | MSB_FIRST = 0 | |
0c3089c1 | 38 | LSB_FIRST = 1 |
238b4080 | 39 | |
c94c8c91 UH |
40 | spi_mode = { |
41 | (0, 0): 0, # Mode 0 | |
42 | (0, 1): 1, # Mode 1 | |
43 | (1, 0): 2, # Mode 2 | |
44 | (1, 1): 3, # Mode 3 | |
45 | } | |
46 | ||
d6bace96 UH |
47 | # Annotation formats |
48 | ANN_HEX = 0 | |
49 | ||
677d597b | 50 | class Decoder(srd.Decoder): |
67e847fd | 51 | id = 'spi' |
2b7d0e2b | 52 | name = 'SPI' |
2b7d0e2b | 53 | longname = 'Serial Peripheral Interface (SPI) bus' |
9a12a6e7 | 54 | desc = '...desc...' |
6eb87578 GM |
55 | longdesc = '...longdesc...' |
56 | author = 'Gareth McMullin' | |
57 | email = 'gareth@blacksphere.co.nz' | |
58 | license = 'gplv2+' | |
59 | inputs = ['logic'] | |
60 | outputs = ['spi'] | |
6b5b91d2 | 61 | probes = [ |
de9cee24 UH |
62 | {'id': 'mosi', 'name': 'MOSI', |
63 | 'desc': 'SPI MOSI line (Master out, slave in)'}, | |
4e570fa9 UH |
64 | {'id': 'miso', 'name': 'MISO', |
65 | 'desc': 'SPI MISO line (Master in, slave out)'}, | |
6b5b91d2 | 66 | {'id': 'sck', 'name': 'CLK', 'desc': 'SPI clock line'}, |
4e570fa9 | 67 | {'id': 'cs', 'name': 'CS#', 'desc': 'SPI CS (chip select) line'}, |
6b5b91d2 | 68 | ] |
238b4080 UH |
69 | options = { |
70 | 'cs_active_low': ['CS# active low', ACTIVE_LOW], | |
c94c8c91 UH |
71 | 'cpol': ['Clock polarity', CPOL_0], |
72 | 'cpha': ['Clock phase', CPHA_0], | |
73 | 'bitorder': ['Bit order within the SPI data', MSB_FIRST], | |
74 | 'wordsize': ['Word size of SPI data', 8], # 1-64? | |
238b4080 | 75 | } |
b1bb5eed | 76 | annotations = [ |
d6bace96 | 77 | ['Hex', 'SPI data bytes in hex format'], |
b1bb5eed | 78 | ] |
6eb87578 | 79 | |
3643fc3f | 80 | def __init__(self): |
c66baa8c | 81 | self.oldsck = 1 |
a10bfc48 | 82 | self.bitcount = 0 |
4917bb31 | 83 | self.mosidata = 0 |
d6bace96 | 84 | self.misodata = 0 |
6eb87578 | 85 | self.bytesreceived = 0 |
d6bace96 | 86 | self.samplenum = -1 |
01329e88 | 87 | self.cs_was_deasserted_during_data_word = 0 |
6eb87578 | 88 | |
0db89774 UH |
89 | # Set protocol decoder option defaults. |
90 | self.cs_active_low = Decoder.options['cs_active_low'][1] | |
c94c8c91 UH |
91 | self.cpol = Decoder.options['cpol'][1] |
92 | self.cpha = Decoder.options['cpha'][1] | |
93 | self.bitorder = Decoder.options['bitorder'][1] | |
94 | self.wordsize = Decoder.options['wordsize'][1] | |
0db89774 | 95 | |
3643fc3f | 96 | def start(self, metadata): |
d6bace96 | 97 | self.out_proto = self.add(srd.OUTPUT_PROTO, 'spi') |
56202222 | 98 | self.out_ann = self.add(srd.OUTPUT_ANN, 'spi') |
3643fc3f | 99 | |
6eb87578 | 100 | def report(self): |
e100d51e | 101 | return 'SPI: %d bytes received' % self.bytesreceived |
6eb87578 | 102 | |
2b9837d9 | 103 | def decode(self, ss, es, data): |
6b5b91d2 UH |
104 | # HACK! At the moment the number of probes is not handled correctly. |
105 | # E.g. if an input file (-i foo.sr) has more than two probes enabled. | |
de9cee24 | 106 | # for (samplenum, (mosi, sck, x, y, z, a)) in data: |
b1bb5eed | 107 | # for (samplenum, (cs, miso, sck, mosi, wp, hold)) in data: |
de9cee24 | 108 | for (samplenum, (cs, miso, sck, mosi, wp, hold)) in data: |
6eb87578 | 109 | |
d6bace96 UH |
110 | self.samplenum += 1 # FIXME |
111 | ||
c94c8c91 | 112 | # Ignore sample if the clock pin hasn't changed. |
6eb87578 GM |
113 | if sck == self.oldsck: |
114 | continue | |
c94c8c91 | 115 | |
6eb87578 | 116 | self.oldsck = sck |
c94c8c91 UH |
117 | |
118 | # Sample data on rising/falling clock edge (depends on mode). | |
119 | mode = spi_mode[self.cpol, self.cpha] | |
120 | if mode == 0 and sck == 0: # Sample on rising clock edge | |
121 | continue | |
122 | elif mode == 1 and sck == 1: # Sample on falling clock edge | |
123 | continue | |
124 | elif mode == 2 and sck == 1: # Sample on falling clock edge | |
125 | continue | |
126 | elif mode == 3 and sck == 0: # Sample on rising clock edge | |
127 | continue | |
6eb87578 | 128 | |
d6bace96 | 129 | # If this is the first bit, save its sample number. |
a10bfc48 | 130 | if self.bitcount == 0: |
d6bace96 | 131 | self.start_sample = samplenum |
01329e88 UH |
132 | if cs: |
133 | self.cs_was_deasserted_during_data_word = 1 | |
b1bb5eed | 134 | |
1ea831e9 | 135 | # Receive MOSI bit into our shift register. |
c94c8c91 | 136 | if self.bitorder == MSB_FIRST: |
cc204746 | 137 | self.mosidata |= mosi << (self.wordsize - 1 - self.bitcount) |
1ea831e9 UH |
138 | else: |
139 | self.mosidata |= mosi << self.bitcount | |
140 | ||
141 | # Receive MISO bit into our shift register. | |
c94c8c91 | 142 | if self.bitorder == MSB_FIRST: |
cc204746 | 143 | self.misodata |= miso << (self.wordsize - 1 - self.bitcount) |
1ea831e9 UH |
144 | else: |
145 | self.misodata |= miso << self.bitcount | |
b1bb5eed | 146 | |
a10bfc48 | 147 | self.bitcount += 1 |
b1bb5eed UH |
148 | |
149 | # Continue to receive if not a byte yet. | |
cc204746 | 150 | if self.bitcount != self.wordsize: |
6eb87578 | 151 | continue |
b1bb5eed | 152 | |
d6bace96 UH |
153 | self.put(self.start_sample, self.samplenum, self.out_proto, |
154 | ['data', self.mosidata, self.misodata]) | |
155 | self.put(self.start_sample, self.samplenum, self.out_ann, | |
156 | [ANN_HEX, ['MOSI: 0x%02x, MISO: 0x%02x' % (self.mosidata, | |
157 | self.misodata)]]) | |
b1bb5eed | 158 | |
01329e88 UH |
159 | if self.cs_was_deasserted_during_data_word: |
160 | self.put(self.start_sample, self.samplenum, self.out_ann, | |
161 | [ANN_HEX, ['WARNING: CS# was deasserted!']]) | |
162 | ||
b1bb5eed | 163 | # Reset decoder state. |
4917bb31 | 164 | self.mosidata = 0 |
d6bace96 | 165 | self.misodata = 0 |
a10bfc48 | 166 | self.bitcount = 0 |
b1bb5eed UH |
167 | |
168 | # Keep stats for summary. | |
6eb87578 | 169 | self.bytesreceived += 1 |
ad2dc0de | 170 |