| | 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 | |
| | 21 | def decode(inbuf): |
| | 22 | """Counts the low->high and high->low transitions in the specified |
| | 23 | channel(s) of the signal.""" |
| | 24 | |
| | 25 | outbuf = '' |
| | 26 | |
| | 27 | # FIXME: Get the data in the correct format in the first place. |
| | 28 | inbuf = [ord(x) for x in inbuf] |
| | 29 | |
| | 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 |
| | 37 | |
| | 38 | # Initial values. |
| | 39 | oldbyte = inbuf[0] |
| | 40 | for i in range(channels): |
| | 41 | oldbit[i] = (oldbyte & (1 << i)) >> i |
| | 42 | |
| | 43 | # Loop over all samples. |
| | 44 | # TODO: Handle LAs with more/less than 8 channels. |
| | 45 | for s in inbuf: |
| | 46 | # Optimization: Skip identical bytes (no transitions). |
| | 47 | if oldbyte == s: |
| | 48 | continue |
| | 49 | for i in range(channels): |
| | 50 | curbit = (s & (1 << i)) >> i |
| | 51 | # Optimization: Skip identical bits (no transitions). |
| | 52 | if oldbit[i] == curbit: |
| | 53 | continue |
| | 54 | elif (oldbit[i] == 0 and curbit == 1): |
| | 55 | rising[i] += 1 |
| | 56 | elif (oldbit[i] == 1 and curbit == 0): |
| | 57 | falling[i] += 1 |
| | 58 | oldbit[i] = curbit |
| | 59 | oldbyte = s |
| | 60 | |
| | 61 | # Total number of transitions is the sum of rising and falling edges. |
| | 62 | for i in range(channels): |
| | 63 | transitions[i] = rising[i] + falling[i] |
| | 64 | |
| | 65 | outbuf += "Rising edges: " |
| | 66 | for i in range(channels): |
| | 67 | outbuf += str(rising[i]) + " " |
| | 68 | outbuf += "\nFalling edges: " |
| | 69 | for i in range(channels): |
| | 70 | outbuf += str(falling[i]) + " " |
| | 71 | outbuf += "\nTransitions: " |
| | 72 | for i in range(channels): |
| | 73 | outbuf += str(transitions[i]) + " " |
| | 74 | outbuf += "\n" |
| | 75 | |
| | 76 | return outbuf |
| | 77 | |
| | 78 | def register(): |
| | 79 | return { |
| | 80 | 'id': 'transitioncounter', |
| | 81 | 'name': 'Transition counter', |
| | 82 | 'desc': 'Count rising/falling edges', |
| | 83 | 'inputformats': ['raw'], |
| | 84 | 'signalnames': {}, # FIXME |
| | 85 | 'outputformats': ['transitioncounts'], |
| | 86 | } |
| | 87 | |
| | 88 | # Use psyco (if available) as it results in huge performance improvements. |
| | 89 | try: |
| | 90 | import psyco |
| | 91 | psyco.bind(decode) |
| | 92 | except ImportError: |
| | 93 | pass |
| | 94 | |
projects / libsigrokdecode.git / blame_incremental