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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, write to the Free Software
- ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- ##
- import sigrokdecode as srd
- from collections import deque
- class SamplerateError(Exception):
- pass
- def normalize_time(t):
- if t >= 1.0:
- return '%.3f s (%.3f Hz)' % (t, (1/t))
- elif 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 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 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 Decoder(srd.Decoder):
- api_version = 2
- id = 'timing'
- name = 'Timing'
- longname = 'Timing calculation with Frequency and Averaging'
- desc = 'Calculate time between edges.'
- license = 'gplv2+'
- inputs = ['logic']
- outputs = ['timing']
- channels = (
- {'id': 'data', 'name': 'Data', 'desc': 'Data line'},
- )
- annotations = (
- ('time', 'Time'),
- ('average', 'Average'),
- )
- annotation_rows = (
- ('time', 'Time', (0,)),
- ('average', 'Average', (1,)),
- )
- options = (
- { 'id': 'avg-period', 'desc': 'Averaging Period', 'default': 100 },
- )
- def __init__(self, **kwargs):
- self.samplerate = None
- self.oldpin = None
- self.last_samplenum = None
- self.last_n = deque()
- self.chunks = 0
- 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, ss, es, data):
- if not self.samplerate:
- raise SamplerateError('Cannot decode without samplerate.')
- for (samplenum, (pin,)) in data:
- if self.oldpin is None:
- self.oldpin = pin
- self.last_samplenum = samplenum
- continue
- # It seems that the decoder gets passed the same samples
- # over and over again sometimes, so we have to make sure
- # we are only looking at samples we have not already seen
- # otherwise a big mess happens.
- if self.last_samplenum >= samplenum:
- continue
- if self.oldpin != pin:
- # print('%d %s' % (samplenum, pin))
- samples = samplenum - self.last_samplenum
- t = samples / self.samplerate
- self.chunks += 1
- # Don't insert the first chunk into the averaging as it is
- # not complete probably.
- if self.last_samplenum is None or self.chunks < 2:
- # Report the timing normalized.
- self.put(self.last_samplenum, samplenum, self.out_ann,
- [0, [normalize_time(t)]])
- else:
- if t > 0:
- self.last_n.append(t)
- # print (self.last_n)
- if len(self.last_n) > self.options['avg-period']:
- self.last_n.popleft()
- #if len(self.last_n) < 2:
- # self.put(self.last_samplenum, samplenum, self.out_ann,
- # [0, [normalize_time(t) ]])
- #else:
- # Report the timing normalized.
- self.put(self.last_samplenum, samplenum, self.out_ann,
- [0, [normalize_time(t)]])
- self.put(self.last_samplenum, samplenum, self.out_ann,
- [1, [normalize_time(sum(self.last_n)/len(self.last_n))]])
- # Store data for next round.
- self.last_samplenum = samplenum
- self.oldpin = pin
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