1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
##
## 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
class SamplerateError(Exception):
pass
def normalize_time(t):
if t >= 1.0:
return '%.3f s' % t
elif t >= 0.001:
return '%.3f ms' % (t * 1000.0)
elif t >= 0.000001:
return '%.3f μs' % (t * 1000.0 * 1000.0)
elif t >= 0.000000001:
return '%.3f ns' % (t * 1000.0 * 1000.0 * 1000.0)
else:
return '%f' % t
class Decoder(srd.Decoder):
api_version = 2
id = 'timing'
name = 'Timing'
longname = 'Timing calculation'
desc = 'Calculate time between edges.'
license = 'gplv2+'
inputs = ['logic']
outputs = ['timing']
channels = (
{'id': 'data', 'name': 'Data', 'desc': 'Data line'},
)
annotations = (
('time', 'Time'),
)
annotation_rows = (
('time', 'Time', (0,)),
)
def __init__(self, **kwargs):
self.samplerate = None
self.oldpin = None
self.last_samplenum = 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, ss, es, data):
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
for (samplenum, (pin,)) in data:
# Ignore identical samples early on (for performance reasons).
if self.oldpin == pin:
continue
if self.oldpin is None:
self.oldpin = pin
self.last_samplenum = samplenum
continue
if self.oldpin != pin:
samples = samplenum - self.last_samplenum
t = samples / self.samplerate
# Report the timing normalized.
self.put(self.last_samplenum, samplenum, self.out_ann,
[0, [normalize_time(t)]])
# Store data for next round.
self.last_samplenum = samplenum
self.oldpin = pin
|
