## ## This file is part of the sigrok project. ## ## Copyright (C) 2011-2012 Uwe Hermann ## ## 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 # Annotation feed formats ANN_ASCII = 0 ANN_DEC = 1 ANN_HEX = 2 ANN_OCT = 3 ANN_BITS = 4 class Decoder(srd.Decoder): api_version = 1 id = 'onewire' name = '1-Wire' longname = '' desc = '1-Wire bus and MicroLan' license = 'gplv2+' inputs = ['logic'] outputs = ['onewire'] probes = [ {'id': 'owr', 'name': 'OWR', 'desc': '1-Wire bus'}, ] optional_probes = [ {'id': 'pwr', 'name': 'PWR', 'desc': '1-Wire power'}, ] options = { 'overdrive': ['Overdrive', 0], } annotations = [ ['ASCII', 'Data bytes as ASCII characters'], ['Decimal', 'Databytes as decimal, integer values'], ['Hex', 'Data bytes in hex format'], ['Octal', 'Data bytes as octal numbers'], ['Bits', 'Data bytes in bit notation (sequence of 0/1 digits)'], ] def putx(self, data): self.put(self.startsample, self.samplenum - 1, self.out_ann, data) def __init__(self, **kwargs): # Common variables self.samplenum = 0 # Link layer variables self.lnk_state = 'WAIT FOR NEGEDGE' self.lnk_event = 'NONE' self.lnk_start = -1 self.lnk_bit = -1 self.lnk_cnt = 0 self.lnk_byte = -1 # Network layer variables self.net_state = 'WAIT FOR EVENT' self.net_event = 'NONE' self.net_command = -1 # Transport layer variables self.trn_state = 'WAIT FOR EVENT' self.trn_event = 'NONE' self.data_sample = -1 self.cur_data_bit = 0 self.databyte = 0 self.startsample = -1 def start(self, metadata): self.samplerate = metadata['samplerate'] self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire') self.out_ann = self.add(srd.OUTPUT_ANN , 'onewire') # The width of the 1-Wire time base (30us) in number of samples. # TODO: optimize this value self.time_base = float(self.samplerate) / float(0.000030) def report(self): pass def decode(self, ss, es, data): for (self.samplenum, owr) in data: # Data link layer # Clear events. self.lnk_event = "RESET" # State machine. if self.lnk_state == 'WAIT FOR FALLING EDGE': # The start of a cycle is a falling edge. if (owr == 0): # Save the sample number for the falling edge. self.lnk_fall = self.samplenum # Go to waiting for sample time self.lnk_state = 'WAIT FOR DATA SAMPLE' elif self.lnk_state == 'WAIT FOR DATA SAMPLE': # Data should be sample one 'time unit' after a falling edge if (self.samplenum - self.lnk_fall == 1*self.time_base): self.lnk_bit = owr & 0x1 self.lnk_event = "DATA BIT" if (self.lnk_bit) : self.lnk_state = 'WAIT FOR FALLING EDGE' else : self.lnk_state = 'WAIT FOR RISING EDGE' elif self.lnk_state == 'WAIT FOR RISING EDGE': # The end of a cycle is a rising edge. if (owr == 1): # A reset cycle is longer than 8T if (self.samplenum - self.lnk_fall > 8*self.time_base): # Save the sample number for the falling edge. self.lnk_rise = self.samplenum # Send a reset event to the next protocol layer self.lnk_event = "RESET" self.lnk_state = "WAIT FOR PRESENCE DETECT" elif self.lnk_state == 'WAIT FOR PRESENCE DETECT': # Data should be sample one 'time unit' after a falling edge if (self.samplenum - self.lnk_rise == 2.5*self.time_base): self.lnk_bit = owr & 0x1 self.lnk_event = "PRESENCE DETECT" if (self.lnk_bit) : self.lnk_state = 'WAIT FOR FALLING EDGE' else : self.lnk_state = 'WAIT FOR RISING EDGE' else: raise Exception('Invalid lnk_state: %d' % self.lnk_state) # Network layer # Clear events. self.net_event = "RESET" # State machine. if (self.lnk_event == "RESET"): self.net_state = "WAIT FOR COMMAND" self.net_cnt = 0 self.net_cmd = 0 elif (self.lnk_event == "DATA BIT"): if (self.net_state == "WAIT FOR COMMAND"): self.net_cnt = self.net_cnt + 1 self.net_cmd = (self.net_cmd << 1) & self.lnk_bit if (self.lnk_cnt == 8): self.put(self.startsample, self.samplenum, self.out_proto, ['LNK: BYTE', self.lnk_byte]) self.put(self.startsample, self.samplenum, self.out_ann , ['LNK: BYTE', self.lnk_byte]) if (self.net_cmd == 0x33): # READ ROM break elif (self.net_cmd == 0x0f): # READ ROM break elif (self.net_cmd == 0xcc): # SKIP ROM break elif (self.net_cmd == 0x55): # MATCH ROM break elif (self.net_cmd == 0xf0): # SEARCH ROM break elif (self.net_cmd == 0x3c): # OVERDRIVE SKIP ROM break elif (self.net_cmd == 0x69): # OVERDRIVE MATCH ROM break self.lnk_cnt = 0 if (self.net_state == "WAIT FOR ROM"): # break else: raise Exception('Invalid net_state: %d' % self.net_state) elif not (self.lnk_event == "NONE"): raise Exception('Invalid net_event: %d' % self.net_event) # if (self.samplenum == self.lnk_start + 8*self.time_base): # self.put(self.startsample, self.samplenum - 1, self.out_proto, ['RESET'])