From 9c93add5aeca95c568afab7fe249c0586d8dec6b Mon Sep 17 00:00:00 2001
From: Uwe Hermann <uwe@hermann-uwe.de>
Date: Mon, 10 Jan 2011 23:27:15 +0100
Subject: Rename the scripts/ directory to decoders/.
---
decoders/transitioncounter.py | 94 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 94 insertions(+)
create mode 100644 decoders/transitioncounter.py
(limited to 'decoders/transitioncounter.py')
diff --git a/decoders/transitioncounter.py b/decoders/transitioncounter.py
new file mode 100644
index 0000000..a6d331e
--- /dev/null
+++ b/decoders/transitioncounter.py
@@ -0,0 +1,94 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, write to the Free Software
+## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+##
+
+def decode(inbuf):
+ """Counts the low->high and high->low transitions in the specified
+ channel(s) of the signal."""
+
+ outbuf = ''
+
+ # FIXME: Get the data in the correct format in the first place.
+ inbuf = [ord(x) for x in inbuf]
+
+ # TODO: Don't hardcode the number of channels.
+ channels = 8
+
+ oldbit = [0] * channels
+ transitions = [0] * channels
+ rising = [0] * channels
+ falling = [0] * channels
+
+ # Initial values.
+ oldbyte = inbuf[0]
+ for i in range(channels):
+ oldbit[i] = (oldbyte & (1 << i)) >> i
+
+ # Loop over all samples.
+ # TODO: Handle LAs with more/less than 8 channels.
+ for s in inbuf:
+ # Optimization: Skip identical bytes (no transitions).
+ if oldbyte == s:
+ continue
+ for i in range(channels):
+ curbit = (s & (1 << i)) >> i
+ # Optimization: Skip identical bits (no transitions).
+ if oldbit[i] == curbit:
+ continue
+ elif (oldbit[i] == 0 and curbit == 1):
+ rising[i] += 1
+ elif (oldbit[i] == 1 and curbit == 0):
+ falling[i] += 1
+ oldbit[i] = curbit
+ oldbyte = s
+
+ # Total number of transitions is the sum of rising and falling edges.
+ for i in range(channels):
+ transitions[i] = rising[i] + falling[i]
+
+ outbuf += "Rising edges: "
+ for i in range(channels):
+ outbuf += str(rising[i]) + " "
+ outbuf += "\nFalling edges: "
+ for i in range(channels):
+ outbuf += str(falling[i]) + " "
+ outbuf += "\nTransitions: "
+ for i in range(channels):
+ outbuf += str(transitions[i]) + " "
+ outbuf += "\n"
+
+ return outbuf
+
+def register():
+ return {
+ 'id': 'transitioncounter',
+ 'name': 'Transition counter',
+ 'desc': 'Count rising/falling edges',
+ 'inputformats': ['raw'],
+ 'signalnames': {}, # FIXME
+ 'outputformats': ['transitioncounts'],
+ }
+
+# Use psyco (if available) as it results in huge performance improvements.
+try:
+ import psyco
+ psyco.bind(decode)
+except ImportError:
+ pass
+
--
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