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##
## 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
import sigrokdecode as srd
# a dictionary of FUNCTION commands and their names
command = {
# scratchpad
0x4e: "WRITE SCRATCHPAD",
0xbe: "READ SCRATCHPAD",
0x48: "COPY SCRATCHPAD",
# thermometer
0x44: "CONVERT TEMPERATURE",
0xb4: "READ POWER MODE",
0xb8: "RECALL EEPROM",
0xf5: "PIO ACCESS READ",
0xA5: "PIO ACCESS WRITE",
0x99: "CHAIN",
# memory
0xf0: "READ MEMORY",
0xa5: "EXTENDED READ MEMORY",
0x0f: "WRITE MEMORY",
0x55: "WRITE STATUS",
0xaa: "READ STATUS",
0xf5: "CHANNEL ACCESS"
}
class Decoder(srd.Decoder):
api_version = 1
id = 'maxim_ds28ea00'
name = '1-Wire transport layer'
longname = '1-Wire serial communication bus'
desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
license = 'gplv2+'
inputs = ['onewire_network']
outputs = []
probes = []
optional_probes = []
options = {}
annotations = [
['Transport', 'Transport layer events'],
]
def __init__(self, **kwargs):
# Event timing variables
self.trn_beg = 0
self.trn_end = 0
# Transport layer variables
self.state = 'ROM'
self.rom = 0x0000000000000000
def start(self, metadata):
self.out_ann = self.add(srd.OUTPUT_ANN , 'onewire_transport')
def report(self):
pass
def decode(self, ss, es, data):
[code, val] = data
# State machine.
if (code == "RESET/PRESENCE"):
self.put(ss, es, self.out_ann, [0, ['RESET/PRESENCE: %s' % ('True' if val else 'False')]])
self.state = "ROM"
elif (code == "ROM"):
self.rom = val
self.put(ss, es, self.out_ann, [0, ['ROM: 0x%016x' % (val)]])
self.state = "COMMAND"
elif (code == "DATA"):
if (self.state == "COMMAND"):
if (val in command):
self.put(ss, es, self.out_ann, [0, ['FUNCTION COMMAND: 0x%02x \'%s\'' % (val, command[val])]])
self.state = command[val]
else:
self.put(ss, es, self.out_ann, [0, ['FUNCTION COMMAND: 0x%02x \'%s\'' % (val, 'UNRECOGNIZED')]])
self.state = "UNRECOGNIZED"
elif (self.state == "READ SCRATCHPAD"):
self.put(ss, es, self.out_ann, [0, ['SCRATCHPAD DATA: 0x%02x' % (val)]])
elif (self.state == "CONVERT TEMPERATURE"):
self.put(ss, es, self.out_ann, [0, ['TEMPERATURE CONVERSION STATUS: 0x%02x' % (val)]])
elif (self.state in command.values()):
self.put(ss, es, self.out_ann, [0, ['TODO "%s": 0x%02x' % (self.state, val)]])
elif (self.state == "UNRECOGNIZED"):
self.put(ss, es, self.out_ann, [0, ['UNRECOGNIZED COMMAND: 0x%02x' % (val)]])
else:
raise Exception('Invalid state: %s' % self.state)
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