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##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2014 Torsten Duwe <duwe@suse.de>
## Copyright (C) 2014 Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
##
## 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, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
from collections import deque
class SamplerateError(Exception):
pass
def normalize_time(t):
if abs(t) >= 1.0:
return '%.3f s (%.3f Hz)' % (t, (1/t))
elif abs(t) >= 0.001:
if 1/t/1000 < 1:
return '%.3f ms (%.3f Hz)' % (t * 1000.0, (1/t))
else:
return '%.3f ms (%.3f kHz)' % (t * 1000.0, (1/t)/1000)
elif abs(t) >= 0.000001:
if 1/t/1000/1000 < 1:
return '%.3f μs (%.3f kHz)' % (t * 1000.0 * 1000.0, (1/t)/1000)
else:
return '%.3f μs (%.3f MHz)' % (t * 1000.0 * 1000.0, (1/t)/1000/1000)
elif abs(t) >= 0.000000001:
if 1/t/1000/1000/1000:
return '%.3f ns (%.3f MHz)' % (t * 1000.0 * 1000.0 * 1000.0, (1/t)/1000/1000)
else:
return '%.3f ns (%.3f GHz)' % (t * 1000.0 * 1000.0 * 1000.0, (1/t)/1000/1000/1000)
else:
return '%f' % t
class Pin:
(DATA,) = range(1)
class Ann:
(TIME, AVG, DELTA,) = range(3)
class Decoder(srd.Decoder):
api_version = 3
id = 'timing'
name = 'Timing'
longname = 'Timing calculation with frequency and averaging'
desc = 'Calculate time between edges.'
license = 'gplv2+'
inputs = ['logic']
outputs = []
tags = ['Clock/timing', 'Util']
channels = (
{'id': 'data', 'name': 'Data', 'desc': 'Data line'},
)
annotations = (
('time', 'Time'),
('average', 'Average'),
('delta', 'Delta'),
)
annotation_rows = (
('times', 'Times', (Ann.TIME,)),
('averages', 'Averages', (Ann.AVG,)),
('deltas', 'Deltas', (Ann.DELTA,)),
)
options = (
{ 'id': 'avg_period', 'desc': 'Averaging period', 'default': 100 },
{ 'id': 'edge', 'desc': 'Edges to check', 'default': 'any', 'values': ('any', 'rising', 'falling') },
{ 'id': 'delta', 'desc': 'Show delta from last', 'default': 'no', 'values': ('yes', 'no') },
)
def __init__(self):
self.reset()
def reset(self):
self.samplerate = None
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
def decode(self):
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
edge = self.options['edge']
avg_period = self.options['avg_period']
last_samplenum = None
last_n = deque()
last_t = None
while True:
if edge == 'rising':
pin = self.wait({Pin.DATA: 'r'})
elif edge == 'falling':
pin = self.wait({Pin.DATA: 'f'})
else:
pin = self.wait({Pin.DATA: 'e'})
if not last_samplenum:
last_samplenum = self.samplenum
continue
samples = self.samplenum - last_samplenum
t = samples / self.samplerate
if t > 0:
last_n.append(t)
if len(last_n) > avg_period:
last_n.popleft()
self.put(last_samplenum, self.samplenum, self.out_ann,
[Ann.TIME, [normalize_time(t)]])
if avg_period > 0:
self.put(last_samplenum, self.samplenum, self.out_ann,
[Ann.AVG, [normalize_time(sum(last_n) / len(last_n))]])
if last_t and self.options['delta'] == 'yes':
self.put(last_samplenum, self.samplenum, self.out_ann,
[Ann.DELTA, [normalize_time(t - last_t)]])
last_t = t
last_samplenum = self.samplenum
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