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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 | ||
5c55017c | 21 | def decode(inbuf): |
1c6fa20f UH |
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 | 37 | |
a156f09e | 38 | # Initial values. |
c11d3c15 | 39 | oldbyte = inbuf[0] |
a5fdab45 | 40 | for i in range(channels): |
930bd9d9 | 41 | oldbit[i] = (oldbyte & (1 << i)) >> i |
d0f3d677 UH |
42 | |
43 | # Loop over all samples. | |
44 | # TODO: Handle LAs with more/less than 8 channels. | |
45 | for s in inbuf: | |
c11d3c15 UH |
46 | # Optimization: Skip identical bytes (no transitions). |
47 | if oldbyte == s: | |
48 | continue | |
a5fdab45 | 49 | for i in range(channels): |
930bd9d9 | 50 | curbit = (s & (1 << i)) >> i |
c11d3c15 UH |
51 | # Optimization: Skip identical bits (no transitions). |
52 | if oldbit[i] == curbit: | |
53 | continue | |
54 | elif (oldbit[i] == 0 and curbit == 1): | |
d0f3d677 UH |
55 | rising[i] += 1 |
56 | elif (oldbit[i] == 1 and curbit == 0): | |
57 | falling[i] += 1 | |
58 | oldbit[i] = curbit | |
a156f09e | 59 | oldbyte = s |
d0f3d677 UH |
60 | |
61 | # Total number of transitions is the sum of rising and falling edges. | |
a5fdab45 | 62 | for i in range(channels): |
d0f3d677 UH |
63 | transitions[i] = rising[i] + falling[i] |
64 | ||
65 | outbuf += "Rising edges: " | |
a5fdab45 | 66 | for i in range(channels): |
d0f3d677 UH |
67 | outbuf += str(rising[i]) + " " |
68 | outbuf += "\nFalling edges: " | |
a5fdab45 | 69 | for i in range(channels): |
d0f3d677 UH |
70 | outbuf += str(falling[i]) + " " |
71 | outbuf += "\nTransitions: " | |
a5fdab45 | 72 | for i in range(channels): |
d0f3d677 UH |
73 | outbuf += str(transitions[i]) + " " |
74 | outbuf += "\n" | |
1c6fa20f | 75 | |
1c6fa20f UH |
76 | return outbuf |
77 | ||
6fe63193 | 78 | def register(): |
79 | return { | |
80 | 'id': 'transitioncounter', | |
81 | 'name': 'Transition counter', | |
a156f09e | 82 | 'desc': 'Count rising/falling edges', |
6fe63193 | 83 | 'inputformats': ['raw'], |
84 | 'signalnames': {}, # FIXME | |
85 | 'outputformats': ['transitioncounts'], | |
86 | } | |
87 | ||
887d6cfa UH |
88 | # Use psyco (if available) as it results in huge performance improvements. |
89 | try: | |
90 | import psyco | |
5c55017c | 91 | psyco.bind(decode) |
887d6cfa UH |
92 | except ImportError: |
93 | pass | |
94 |