2 ## This file is part of the libsigrokdecode project.
4 ## Copyright (C) 2013 Uwe Hermann <uwe@hermann-uwe.de>
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.
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.
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
21 # Bitrate / baudrate guessing protocol decoder
23 import sigrokdecode as srd
25 class Decoder(srd.Decoder):
28 name = 'Guess bitrate'
29 longname = 'Guess bitrate/baudrate'
30 desc = 'Guess the bitrate/baudrate of a UART (or other) protocol.'
33 outputs = ['guess_bitrate']
35 {'id': 'data', 'name': 'Data', 'desc': 'Data line'},
40 ['bitrate', 'Bitrate / baudrate'],
44 self.put(self.ss_edge, self.samplenum, self.out_ann, data)
46 def __init__(self, **kwargs):
49 self.first_transition = True
52 def start(self, metadata):
53 self.samplerate = metadata['samplerate']
54 # self.out_proto = self.register(srd.OUTPUT_PYTHON)
55 self.out_ann = self.register(srd.OUTPUT_ANN)
57 def decode(self, ss, es, data):
58 for (self.samplenum, pins) in data:
62 # Wait for any transition on the data line.
63 if data == self.olddata:
66 # Initialize first self.olddata with the first sample value.
67 if self.olddata == None:
71 # Get the smallest distance between two transitions
72 # and use that to calculate the bitrate/baudrate.
73 if self.first_transition == True:
74 self.ss_edge = self.samplenum
75 self.first_transition = False
77 b = self.samplenum - self.ss_edge
78 if self.bitwidth == None or b < self.bitwidth:
80 bitrate = int(float(self.samplerate) / float(b))
81 self.putx([0, ['%d' % bitrate]])
82 self.ss_edge = self.samplenum