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1c6fa20f UH |
1 | ## |
2 | ## This file is part of the sigrok project. | |
3 | ## | |
4 | ## Copyright (C) 2010 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 | ||
1c6fa20f UH |
21 | def sigrokdecode_count_transitions(inbuf): |
22 | """Counts the low->high and high->low transitions in the specified | |
23 | channel(s) of the signal.""" | |
24 | ||
d0f3d677 UH |
25 | outbuf = '' |
26 | ||
c11d3c15 UH |
27 | # FIXME: Get the data in the correct format in the first place. |
28 | inbuf = [ord(x) for x in inbuf] | |
29 | ||
d0f3d677 UH |
30 | # TODO: Don't hardcode the number of channels. |
31 | channels = 8 | |
32 | ||
33 | oldbit = [0] * channels | |
34 | transitions = [0] * channels | |
35 | rising = [0] * channels | |
36 | falling = [0] * channels | |
1c6fa20f UH |
37 | |
38 | # print len(inbuf) | |
39 | # print type(inbuf) | |
40 | ||
d0f3d677 | 41 | # Presets... |
c11d3c15 | 42 | oldbyte = inbuf[0] |
a5fdab45 | 43 | for i in range(channels): |
c11d3c15 | 44 | oldbit[i] = (oldbyte & (1 << i)) != 0 |
d0f3d677 UH |
45 | |
46 | # Loop over all samples. | |
47 | # TODO: Handle LAs with more/less than 8 channels. | |
48 | for s in inbuf: | |
c11d3c15 UH |
49 | # Optimization: Skip identical bytes (no transitions). |
50 | if oldbyte == s: | |
51 | continue | |
a5fdab45 | 52 | for i in range(channels): |
d0f3d677 | 53 | curbit = (s & (1 << i) != 0) |
c11d3c15 UH |
54 | # Optimization: Skip identical bits (no transitions). |
55 | if oldbit[i] == curbit: | |
56 | continue | |
57 | elif (oldbit[i] == 0 and curbit == 1): | |
d0f3d677 UH |
58 | rising[i] += 1 |
59 | elif (oldbit[i] == 1 and curbit == 0): | |
60 | falling[i] += 1 | |
61 | oldbit[i] = curbit | |
62 | ||
63 | # Total number of transitions is the sum of rising and falling edges. | |
a5fdab45 | 64 | for i in range(channels): |
d0f3d677 UH |
65 | transitions[i] = rising[i] + falling[i] |
66 | ||
67 | outbuf += "Rising edges: " | |
a5fdab45 | 68 | for i in range(channels): |
d0f3d677 UH |
69 | outbuf += str(rising[i]) + " " |
70 | outbuf += "\nFalling edges: " | |
a5fdab45 | 71 | for i in range(channels): |
d0f3d677 UH |
72 | outbuf += str(falling[i]) + " " |
73 | outbuf += "\nTransitions: " | |
a5fdab45 | 74 | for i in range(channels): |
d0f3d677 UH |
75 | outbuf += str(transitions[i]) + " " |
76 | outbuf += "\n" | |
1c6fa20f | 77 | |
1c6fa20f UH |
78 | return outbuf |
79 | ||
887d6cfa UH |
80 | # Use psyco (if available) as it results in huge performance improvements. |
81 | try: | |
82 | import psyco | |
83 | psyco.bind(sigrokdecode_count_transitions) | |
84 | except ImportError: | |
85 | pass | |
86 |