+++ /dev/null
-##
-## This file is part of the sigrok project.
-##
-## Copyright (C) 2012 Iztok Jeras <iztok.jeras@gmail.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
-##
-
-# 1-Wire protocol decoder (link layer)
-
-import sigrokdecode as srd
-
-class Decoder(srd.Decoder):
- api_version = 1
- id = 'onewire_link'
- name = '1-Wire link layer'
- longname = '1-Wire serial communication bus (link layer)'
- desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
- license = 'gplv2+'
- inputs = ['logic']
- outputs = ['onewire_link']
- probes = [
- {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire signal line'},
- ]
- optional_probes = [
- {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power supply pin'},
- ]
- options = {
- 'overdrive': ['Overdrive', 1],
- # Time options (specified in number of samplerate periods):
- 'cnt_normal_bit': ['Normal mode sample bit time', 0],
- 'cnt_normal_slot': ['Normal mode data slot time', 0],
- 'cnt_normal_presence': ['Normal mode sample presence time', 0],
- 'cnt_normal_reset': ['Normal mode reset time', 0],
- 'cnt_overdrive_bit': ['Overdrive mode sample bit time', 0],
- 'cnt_overdrive_slot': ['Overdrive mode data slot time', 0],
- 'cnt_overdrive_presence': ['Overdrive mode sample presence time', 0],
- 'cnt_overdrive_reset': ['Overdrive mode reset time', 0],
- }
- annotations = [
- ['Text', 'Human-readable text'],
- ['Warnings', 'Human-readable warnings'],
- ]
-
- def __init__(self, **kwargs):
- self.samplenum = 0
- self.state = 'WAIT FOR FALLING EDGE'
- self.present = 0
- self.bit = 0
- self.bit_cnt = 0
- self.command = 0
- self.overdrive = 0
- self.fall = 0
- self.rise = 0
-
- def start(self, metadata):
- self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_link')
- self.out_ann = self.add(srd.OUTPUT_ANN, 'onewire_link')
-
- self.samplerate = metadata['samplerate']
-
- # Check if samplerate is appropriate.
- if self.options['overdrive']:
- if self.samplerate < 2000000:
- self.put(0, 0, self.out_ann, [1,
- ['ERROR: Sampling rate is too low. Must be above 2MHz ' +
- 'for proper overdrive mode decoding.']])
- elif self.samplerate < 5000000:
- self.put(0, 0, self.out_ann, [1,
- ['WARNING: Sampling rate is suggested to be above 5MHz ' +
- 'for proper overdrive mode decoding.']])
- else:
- if self.samplerate < 400000:
- self.put(0, 0, self.out_ann, [1,
- ['ERROR: Sampling rate is too low. Must be above ' +
- '400kHz for proper normal mode decoding.']])
- elif (self.samplerate < 1000000):
- self.put(0, 0, self.out_ann, [1,
- ['WARNING: Sampling rate is suggested to be above ' +
- '1MHz for proper normal mode decoding.']])
-
- # The default 1-Wire time base is 30us. This is used to calculate
- # sampling times.
- samplerate = float(self.samplerate)
- if self.options['cnt_normal_bit']:
- self.cnt_normal_bit = self.options['cnt_normal_bit']
- else:
- self.cnt_normal_bit = int(samplerate * 0.000015) - 1 # 15ns
- if self.options['cnt_normal_slot']:
- self.cnt_normal_slot = self.options['cnt_normal_slot']
- else:
- self.cnt_normal_slot = int(samplerate * 0.000060) - 1 # 60ns
- if self.options['cnt_normal_presence']:
- self.cnt_normal_presence = self.options['cnt_normal_presence']
- else:
- self.cnt_normal_presence = int(samplerate * 0.000075) - 1 # 75ns
- if self.options['cnt_normal_reset']:
- self.cnt_normal_reset = self.options['cnt_normal_reset']
- else:
- self.cnt_normal_reset = int(samplerate * 0.000480) - 1 # 480ns
- if self.options['cnt_overdrive_bit']:
- self.cnt_overdrive_bit = self.options['cnt_overdrive_bit']
- else:
- self.cnt_overdrive_bit = int(samplerate * 0.000002) - 1 # 2ns
- if self.options['cnt_overdrive_slot']:
- self.cnt_overdrive_slot = self.options['cnt_overdrive_slot']
- else:
- self.cnt_overdrive_slot = int(samplerate * 0.0000073) - 1 # 6ns+1.3ns
- if self.options['cnt_overdrive_presence']:
- self.cnt_overdrive_presence = self.options['cnt_overdrive_presence']
- else:
- self.cnt_overdrive_presence = int(samplerate * 0.000010) - 1 # 10ns
- if self.options['cnt_overdrive_reset']:
- self.cnt_overdrive_reset = self.options['cnt_overdrive_reset']
- else:
- self.cnt_overdrive_reset = int(samplerate * 0.000048) - 1 # 48ns
-
- # Organize values into lists.
- self.cnt_bit = [self.cnt_normal_bit, self.cnt_overdrive_bit]
- self.cnt_presence = [self.cnt_normal_presence, self.cnt_overdrive_presence]
- self.cnt_reset = [self.cnt_normal_reset, self.cnt_overdrive_reset]
- self.cnt_slot = [self.cnt_normal_slot, self.cnt_overdrive_slot]
-
- # Check if sample times are in the allowed range.
-
- time_min = float(self.cnt_normal_bit) / self.samplerate
- time_max = float(self.cnt_normal_bit + 1) / self.samplerate
- if (time_min < 0.000005) or (time_max > 0.000015):
- self.put(0, 0, self.out_ann, [1,
- ['WARNING: The normal mode data sample time interval ' +
- '(%2.1fus-%2.1fus) should be inside (5.0us, 15.0us).'
- % (time_min * 1000000, time_max * 1000000)]])
-
- time_min = float(self.cnt_normal_presence) / self.samplerate
- time_max = float(self.cnt_normal_presence + 1) / self.samplerate
- if (time_min < 0.0000681) or (time_max > 0.000075):
- self.put(0, 0, self.out_ann, [1,
- ['WARNING: The normal mode presence sample time interval ' +
- '(%2.1fus-%2.1fus) should be inside (68.1us, 75.0us).'
- % (time_min * 1000000, time_max * 1000000)]])
-
- time_min = float(self.cnt_overdrive_bit) / self.samplerate
- time_max = float(self.cnt_overdrive_bit + 1) / self.samplerate
- if (time_min < 0.000001) or (time_max > 0.000002):
- self.put(0, 0, self.out_ann, [1,
- ['WARNING: The overdrive mode data sample time interval ' +
- '(%2.1fus-%2.1fus) should be inside (1.0us, 2.0us).'
- % (time_min * 1000000, time_max * 1000000)]])
-
- time_min = float(self.cnt_overdrive_presence) / self.samplerate
- time_max = float(self.cnt_overdrive_presence + 1) / self.samplerate
- if (time_min < 0.0000073) or (time_max > 0.000010):
- self.put(0, 0, self.out_ann, [1,
- ['WARNING: The overdrive mode presence sample time interval ' +
- '(%2.1fus-%2.1fus) should be inside (7.3us, 10.0us).'
- % (time_min*1000000, time_max*1000000)]])
-
- def report(self):
- pass
-
- def decode(self, ss, es, data):
- for (self.samplenum, (owr, pwr)) in data:
- # State machine.
- if self.state == 'WAIT FOR FALLING EDGE':
- # The start of a cycle is a falling edge.
- if owr != 0:
- continue
- # Save the sample number for the falling edge.
- self.fall = self.samplenum
- # Go to waiting for sample time.
- self.state = 'WAIT FOR DATA SAMPLE'
- elif self.state == 'WAIT FOR DATA SAMPLE':
- # Sample data bit.
- t = self.samplenum - self.fall
- if t == self.cnt_bit[self.overdrive]:
- self.bit = owr
- self.state = 'WAIT FOR DATA SLOT END'
- elif self.state == 'WAIT FOR DATA SLOT END':
- # A data slot ends in a recovery period, otherwise, this is
- # probably a reset.
- t = self.samplenum - self.fall
- if t != self.cnt_slot[self.overdrive]:
- continue
-
- if owr == 0:
- # This seems to be a reset slot, wait for its end.
- self.state = 'WAIT FOR RISING EDGE'
- continue
-
- self.put(self.fall, self.samplenum, self.out_ann,
- [0, ['Bit: %d' % self.bit]])
- self.put(self.fall, self.samplenum, self.out_proto,
- ['BIT', self.bit])
-
- # Checking the first command to see if overdrive mode
- # should be entered.
- if self.bit_cnt <= 8:
- self.command |= (self.bit << self.bit_cnt)
- elif self.bit_cnt == 8 and self.command in [0x3c, 0x69]:
- self.put(self.fall, self.cnt_bit[self.overdrive],
- self.out_ann, [0, ['Entering overdrive mode']])
- # Increment the bit counter.
- self.bit_cnt += 1
- # Wait for next slot.
- self.state = 'WAIT FOR FALLING EDGE'
- elif self.state == 'WAIT FOR RISING EDGE':
- # The end of a cycle is a rising edge.
- if owr != 1:
- continue
-
- # Check if this was a reset cycle.
- t = self.samplenum - self.fall
- if t > self.cnt_normal_reset:
- # Save the sample number for the falling edge.
- self.rise = self.samplenum
- self.state = 'WAIT FOR PRESENCE DETECT'
- # Exit overdrive mode.
- if self.overdrive:
- self.put(self.fall, self.cnt_bit[self.overdrive],
- self.out_ann, [0, ['Exiting overdrive mode']])
- self.overdrive = 0
- # Clear command bit counter and data register.
- self.bit_cnt = 0
- self.command = 0
- elif (t > self.cnt_overdrive_reset) and self.overdrive:
- # Save the sample number for the falling edge.
- self.rise = self.samplenum
- self.state = "WAIT FOR PRESENCE DETECT"
- # Otherwise this is assumed to be a data bit.
- else:
- self.state = "WAIT FOR FALLING EDGE"
- elif self.state == 'WAIT FOR PRESENCE DETECT':
- # Sample presence status.
- t = self.samplenum - self.rise
- if t == self.cnt_presence[self.overdrive]:
- self.present = owr
- self.state = 'WAIT FOR RESET SLOT END'
- elif self.state == 'WAIT FOR RESET SLOT END':
- # A reset slot ends in a long recovery period.
- t = self.samplenum - self.rise
- if t != self.cnt_reset[self.overdrive]:
- continue
-
- if owr == 0:
- # This seems to be a reset slot, wait for its end.
- self.state = 'WAIT FOR RISING EDGE'
- continue
-
- self.put(self.fall, self.samplenum, self.out_ann,
- [0, ['Reset/presence: %s'
- % ('false' if self.present else 'true')]])
- self.put(self.fall, self.samplenum, self.out_proto,
- ['RESET/PRESENCE', not self.present])
- # Wait for next slot.
- self.state = 'WAIT FOR FALLING EDGE'
- else:
- raise Exception('Invalid state: %s' % self.state)
projects / libsigrokdecode.git / blobdiff