From 9cfb16e8532e34b40edf1d980c7438afb31668e0 Mon Sep 17 00:00:00 2001
From: Iztok Jeras <iztok.jeras@gmail.com>
Date: Tue, 10 Jul 2012 22:06:58 +0200
Subject: onewire: placing protocol layers into separate directories
---
decoders/onewire_network/Makefile.am | 26 ++++
decoders/onewire_network/__init__.py | 78 ++++++++++++
decoders/onewire_network/onewire_network.py | 177 ++++++++++++++++++++++++++++
3 files changed, 281 insertions(+)
create mode 100644 decoders/onewire_network/Makefile.am
create mode 100644 decoders/onewire_network/__init__.py
create mode 100644 decoders/onewire_network/onewire_network.py
(limited to 'decoders/onewire_network')
diff --git a/decoders/onewire_network/Makefile.am b/decoders/onewire_network/Makefile.am
new file mode 100644
index 0000000..17b3b04
--- /dev/null
+++ b/decoders/onewire_network/Makefile.am
@@ -0,0 +1,26 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## 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
+##
+
+pkgdatadir = $(DECODERS_DIR)/onewire
+
+dist_pkgdata_DATA = __init__.py onewire_link.py onewire_network.py
+
+CLEANFILES = *.pyc
+
diff --git a/decoders/onewire_network/__init__.py b/decoders/onewire_network/__init__.py
new file mode 100644
index 0000000..0a712ef
--- /dev/null
+++ b/decoders/onewire_network/__init__.py
@@ -0,0 +1,78 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## 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.
+
+The 1-Wire protocol enables bidirectional communication over a single wire (and
+ground) between a single master and one or multiple slaves. The protocol is
+layered, the provided parser decodes the next layers:
+- Link layer (reset, presence detection, reading/writing bits)
+- Network layer (skip, search, match device ROM addresses)
+The higher layers (transport, presentation) are not decoded, since they are
+mostly device specific and it would take a lot of code to interpret them.
+
+Sample rate:
+A high enough sample rate is required to properly detect all the elements of
+the protocol. A lower sample rate can be used if the master does not use
+overdrive communication speed. The next minimal values should be used:
+- overdrive available: 2MHz minimum, 5MHz suggested
+- overdrive not available: 400kHz minimum, 1MHz suggested
+
+Probes:
+1-Wire requires a single signal, but some master implementations might have a
+separate signal use to deliver power to the bus during temperature conversion
+as an example. This power signal is currently not parsed.
+- owr (1-Wire bus)
+- pwr (1-Wire power)
+
+Options:
+1-Wire is an asynchronous protocol, so the decoder must know the sample rate.
+The timing for sampling bits, presence and reset is calculated by the decoder,
+but in case the user wishes to use different values, it is possible to
+configure the next timing values (number of sample rate periods):
+- overdrive (if active the decoder will be prepared for overdrive)
+- cnt_normal_bit (time for normal mode sample bit)
+- cnt_normal_presence (time for normal mode sample presence)
+- cnt_normal_reset (time for normal mode reset)
+- cnt_overdrive_bit (time for overdrive mode sample bit)
+- cnt_overdrive_presence (time for overdrive mode sample presence)
+- cnt_overdrive_reset (time for overdrive mode reset)
+This options should be configured only on very rare cases and the user should
+read the decoder source code to understand them correctly.
+
+Annotations:
+Annotations can be shown for each layer of the protocol separately:
+- link (the value of each transmitted bit is shown separately)
+- network (the ROM command, and address are shown)
+- transport (only transport layer byte transfers are shown)
+If link layer annotations are shown, possible issues with sample rate and sample
+timing are also shown.
+
+TODO:
+- add CRC checks for network layer
+- add transport layer code
+- review link layer code, to check for protocol correctness
+- define output protocol
+'''
+
+from .onewire_link import *
+from .onewire_network import *
+
diff --git a/decoders/onewire_network/onewire_network.py b/decoders/onewire_network/onewire_network.py
new file mode 100644
index 0000000..836bce9
--- /dev/null
+++ b/decoders/onewire_network/onewire_network.py
@@ -0,0 +1,177 @@
+##
+## 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
+
+# Annotation feed formats
+ANN_NETWORK = 0
+ANN_TRANSPORT = 1
+
+# a dictionary of ROM commands and their names
+rom_command = {0x33: "READ ROM",
+ 0x0f: "CONDITIONAL READ ROM",
+ 0xcc: "SKIP ROM",
+ 0x55: "MATCH ROM",
+ 0xf0: "SEARCH ROM",
+ 0xec: "CONDITIONAL SEARCH ROM",
+ 0x3c: "OVERDRIVE SKIP ROM",
+ 0x6d: "OVERDRIVE MATCH ROM"}
+
+class Decoder(srd.Decoder):
+ api_version = 1
+ id = 'onewire_network'
+ name = '1-Wire network layer'
+ longname = '1-Wire serial communication bus'
+ desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
+ license = 'gplv2+'
+ inputs = ['onewire_link']
+ outputs = ['onewire_network']
+ probes = []
+ optional_probes = []
+ options = {}
+ annotations = [
+ ['Network', 'Network layer events (device addressing)'],
+ ['Transport', 'Transport layer events'],
+ ]
+
+ def __init__(self, **kwargs):
+ # Event timing variables
+ self.net_beg = 0
+ self.net_end = 0
+ # Network layer variables
+ self.state = 'COMMAND'
+ self.bit_cnt = 0
+ self.search = "P"
+ self.data_p = 0x0
+ self.data_n = 0x0
+ self.data = 0x0
+ self.net_rom = 0x0000000000000000
+
+ def start(self, metadata):
+ self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_network')
+ self.out_ann = self.add(srd.OUTPUT_ANN , 'onewire_network')
+
+ def report(self):
+ pass
+
+ def decode(self, ss, es, data):
+ [code, val] = data
+
+ # State machine.
+ if (self.code == "RESET"):
+ self.state = "COMMAND"
+ self.search = "P"
+ self.bit_cnt = 0
+ elif (self.code == "BIT"):
+ if (self.state == "COMMAND"):
+ # Receiving and decoding a ROM command
+ if (self.onewire_collect(8, val)):
+ self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK,
+ ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, rom_command[self.data])]])
+ if (self.data == 0x33): # READ ROM
+ self.state = "GET ROM"
+ elif (self.data == 0x0f): # CONDITIONAL READ ROM
+ self.state = "GET ROM"
+ elif (self.data == 0xcc): # SKIP ROM
+ self.state = "TRANSPORT"
+ elif (self.data == 0x55): # MATCH ROM
+ self.state = "GET ROM"
+ elif (self.data == 0xf0): # SEARCH ROM
+ self.state = "SEARCH ROM"
+ elif (self.data == 0xec): # CONDITIONAL SEARCH ROM
+ self.state = "SEARCH ROM"
+ elif (self.data == 0x3c): # OVERDRIVE SKIP ROM
+ self.state = "TRANSPORT"
+ elif (self.data == 0x69): # OVERDRIVE MATCH ROM
+ self.state = "GET ROM"
+ elif (self.state == "GET ROM"):
+ # A 64 bit device address is selected
+ # family code (1B) + serial number (6B) + CRC (1B)
+ if (self.onewire_collect(64, val)):
+ self.net_rom = self.data & 0xffffffffffffffff
+ self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]])
+ self.state = "TRANSPORT"
+ elif (self.state == "SEARCH ROM"):
+ # A 64 bit device address is searched for
+ # family code (1B) + serial number (6B) + CRC (1B)
+ if (self.onewire_search(64)):
+ self.net_rom = self.data & 0xffffffffffffffff
+ self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]])
+ self.state = "TRANSPORT"
+ elif (self.state == "TRANSPORT"):
+ # The transport layer is handled in byte sized units
+ if (self.onewire_collect(8, val)):
+ self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK , ['TRANSPORT: 0x%02x' % self.data]])
+ self.put(self.net_beg, self.net_end, self.out_ann, [ANN_TRANSPORT, ['TRANSPORT: 0x%02x' % self.data]])
+ self.put(self.net_beg, self.net_end, self.out_proto, ['transfer', self.data])
+ # TODO: Sending translort layer data to 1-Wire device models
+ else:
+ raise Exception('Invalid state: %s' % self.state)
+
+
+ # Link/Network layer data collector
+ def onewire_collect (self, length, val):
+ # Storing the sampe this sequence begins with
+ if (self.bit_cnt == 1):
+ self.net_beg = self.ss
+ self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+ self.bit_cnt = self.bit_cnt + 1
+ # Storing the sampe this sequence ends with
+ # In case the full length of the sequence is received, return 1
+ if (self.bit_cnt == length):
+ self.net_end = self.es
+ self.data = self.data & ((1<<length)-1)
+ self.bit_cnt = 0
+ return (1)
+ else:
+ return (0)
+
+ # Link/Network layer search collector
+ def onewire_search (self, length):
+ # Storing the sampe this sequence begins with
+ if ((self.bit_cnt == 0) and (self.search == "P")):
+ self.net_beg = self.ss
+ # Master receives an original address bit
+ if (self.search == "P"):
+ self.data_p = self.data_p & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+ self.search = "N"
+ # Master receives a complemented address bit
+ elif (self.search == "N"):
+ self.data_n = self.data_n & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+ self.search = "D"
+ # Master transmits an address bit
+ elif (self.search == "D"):
+ self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+ self.search = "P"
+ self.bit_cnt = self.bit_cnt + 1
+ # Storing the sampe this sequence ends with
+ # In case the full length of the sequence is received, return 1
+ if (self.bit_cnt == length):
+ self.net_end = self.es
+ self.data_p = self.data_p & ((1<<length)-1)
+ self.data_n = self.data_n & ((1<<length)-1)
+ self.data = self.data & ((1<<length)-1)
+ self.search = "P"
+ self.bit_cnt = 0
+ return (1)
+ else:
+ return (0)
--
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