## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2011 Gareth McMullin <gareth@blacksphere.co.nz>
-## Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
+## Copyright (C) 2012-2014 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
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
-# SPI protocol decoder
-
import sigrokdecode as srd
+'''
+OUTPUT_PYTHON format:
+
+SPI packet:
+[<cmd>, <data1>, <data2>]
+
+Commands:
+ - 'DATA': <data1> contains the MISO data, <data2> contains the MOSI data.
+ The data is _usually_ 8 bits (but can also be fewer or more bits).
+ Both data items are Python numbers (not strings), or None if the respective
+ probe was not supplied.
+ - 'BITS': <data1>/<data2> contain a list of bit values in this MISO/MOSI data
+ item, and for each of those also their respective start-/endsample numbers.
+ - 'CS CHANGE': <data1> is the old CS# pin value, <data2> is the new value.
+ Both data items are Python numbers (0/1), not strings.
+
+Examples:
+ ['CS-CHANGE', 1, 0]
+ ['DATA', 0xff, 0x3a]
+ ['BITS', [[1, 80, 82], [1, 83, 84], [1, 85, 86], [1, 87, 88],
+ [1, 89, 90], [1, 91, 92], [1, 93, 94], [1, 95, 96]],
+ [[0, 80, 82], [1, 83, 84], [0, 85, 86], [1, 87, 88],
+ [1, 89, 90], [1, 91, 92], [0, 93, 94], [0, 95, 96]]]
+ ['DATA', 0x65, 0x00]
+ ['DATA', 0xa8, None]
+ ['DATA', None, 0x55]
+ ['CS-CHANGE', 0, 1]
+'''
+
# Key: (CPOL, CPHA). Value: SPI mode.
# Clock polarity (CPOL) = 0/1: Clock is low/high when inactive.
# Clock phase (CPHA) = 0/1: Data is valid on the leading/trailing clock edge.
inputs = ['logic']
outputs = ['spi']
probes = [
- {'id': 'miso', 'name': 'MISO',
- 'desc': 'SPI MISO line (Master in, slave out)'},
- {'id': 'mosi', 'name': 'MOSI',
- 'desc': 'SPI MOSI line (Master out, slave in)'},
- {'id': 'sck', 'name': 'CLK', 'desc': 'SPI clock line'},
- {'id': 'cs', 'name': 'CS#', 'desc': 'SPI CS (chip select) line'},
+ {'id': 'clk', 'name': 'CLK', 'desc': 'Clock'},
+ ]
+ optional_probes = [
+ {'id': 'miso', 'name': 'MISO', 'desc': 'Master in, slave out'},
+ {'id': 'mosi', 'name': 'MOSI', 'desc': 'Master out, slave in'},
+ {'id': 'cs', 'name': 'CS#', 'desc': 'Chip-select'},
]
- optional_probes = [] # TODO
- options = {
- 'cs_polarity': ['CS# polarity', 'active-low'],
- 'cpol': ['Clock polarity', 0],
- 'cpha': ['Clock phase', 0],
- 'bitorder': ['Bit order within the SPI data', 'msb-first'],
- 'wordsize': ['Word size of SPI data', 8], # 1-64?
- 'format': ['Data format', 'hex'],
- }
+ options = (
+ {'id': 'cs_polarity', 'desc': 'CS# polarity', 'default': 'active-low',
+ 'values': ('active-low', 'active-high')},
+ {'id': 'cpol', 'desc': 'Clock polarity', 'default': 0,
+ 'values': (0, 1)},
+ {'id': 'cpha', 'desc': 'Clock phase', 'default': 0,
+ 'values': (0, 1)},
+ {'id': 'bitorder', 'desc': 'Bit order within the SPI data',
+ 'default': 'msb-first', 'values': ('msb-first', 'lsb-first')},
+ {'id': 'wordsize', 'desc': 'Word size of SPI data', 'default': 8},
+ )
annotations = [
- ['MISO/MOSI data', 'MISO/MOSI SPI data'],
- ['MISO data', 'MISO SPI data'],
- ['MOSI data', 'MOSI SPI data'],
- ['Warnings', 'Human-readable warnings'],
+ ['miso-data', 'MISO data'],
+ ['mosi-data', 'MOSI data'],
+ ['miso-bits', 'MISO bits'],
+ ['mosi-bits', 'MOSI bits'],
+ ['warnings', 'Human-readable warnings'],
]
+ annotation_rows = (
+ ('miso-data', 'MISO data', (0,)),
+ ('miso-bits', 'MISO bits', (2,)),
+ ('mosi-data', 'MOSI data', (1,)),
+ ('mosi-bits', 'MOSI bits', (3,)),
+ ('other', 'Other', (4,)),
+ )
def __init__(self):
- self.oldsck = 1
+ self.samplerate = None
+ self.oldclk = 1
self.bitcount = 0
- self.mosidata = 0
- self.misodata = 0
- self.bytesreceived = 0
+ self.misodata = self.mosidata = 0
+ self.misobits = []
+ self.mosibits = []
self.startsample = -1
self.samplenum = -1
- self.cs_was_deasserted_during_data_word = 0
+ self.cs_was_deasserted = False
self.oldcs = -1
self.oldpins = None
+ self.have_cs = self.have_miso = self.have_mosi = None
self.state = 'IDLE'
- def start(self, metadata):
- self.out_proto = self.add(srd.OUTPUT_PROTO, 'spi')
- self.out_ann = self.add(srd.OUTPUT_ANN, 'spi')
+ def metadata(self, key, value):
+ if key == srd.SRD_CONF_SAMPLERATE:
+ self.samplerate = value
- def report(self):
- return 'SPI: %d bytes received' % self.bytesreceived
-
- def putpw(self, data):
- self.put(self.startsample, self.samplenum, self.out_proto, data)
+ def start(self):
+ self.out_python = self.register(srd.OUTPUT_PYTHON)
+ self.out_ann = self.register(srd.OUTPUT_ANN)
+ self.out_bitrate = self.register(srd.OUTPUT_META,
+ meta=(int, 'Bitrate', 'Bitrate during transfers'))
def putw(self, data):
self.put(self.startsample, self.samplenum, self.out_ann, data)
- def handle_bit(self, miso, mosi, sck, cs):
- # If this is the first bit, save its sample number.
+ def putdata(self):
+ # Pass MISO and MOSI bits and then data to the next PD up the stack.
+ so = self.misodata if self.have_miso else None
+ si = self.mosidata if self.have_mosi else None
+ so_bits = self.misobits if self.have_miso else None
+ si_bits = self.mosibits if self.have_mosi else None
+
+ if self.have_miso:
+ ss, es = self.misobits[-1][1], self.misobits[0][2]
+ if self.have_mosi:
+ ss, es = self.mosibits[-1][1], self.mosibits[0][2]
+
+ self.put(ss, es, self.out_python, ['BITS', si_bits, so_bits])
+ self.put(ss, es, self.out_python, ['DATA', si, so])
+
+ # Bit annotations.
+ if self.have_miso:
+ for bit in self.misobits:
+ self.put(bit[1], bit[2], self.out_ann, [2, ['%d' % bit[0]]])
+ if self.have_mosi:
+ for bit in self.mosibits:
+ self.put(bit[1], bit[2], self.out_ann, [3, ['%d' % bit[0]]])
+
+ # Dataword annotations.
+ if self.have_miso:
+ self.put(ss, es, self.out_ann, [0, ['%02X' % self.misodata]])
+ if self.have_mosi:
+ self.put(ss, es, self.out_ann, [1, ['%02X' % self.mosidata]])
+
+ def reset_decoder_state(self):
+ self.misodata = 0 if self.have_miso else None
+ self.mosidata = 0 if self.have_mosi else None
+ self.misobits = [] if self.have_miso else None
+ self.mosibits = [] if self.have_mosi else None
+ self.bitcount = 0
+
+ def handle_bit(self, miso, mosi, clk, cs):
+ # If this is the first bit of a dataword, save its sample number.
if self.bitcount == 0:
self.startsample = self.samplenum
- active_low = (self.options['cs_polarity'] == 'active-low')
- deasserted = cs if active_low else not cs
- if deasserted:
- self.cs_was_deasserted_during_data_word = 1
+ self.cs_was_deasserted = False
+ if self.have_cs:
+ active_low = (self.options['cs_polarity'] == 'active-low')
+ deasserted = (cs == 1) if active_low else (cs == 0)
+ if deasserted:
+ self.cs_was_deasserted = True
ws = self.options['wordsize']
+ # Receive MISO bit into our shift register.
+ if self.have_miso:
+ if self.options['bitorder'] == 'msb-first':
+ self.misodata |= miso << (ws - 1 - self.bitcount)
+ else:
+ self.misodata |= miso << self.bitcount
+
# Receive MOSI bit into our shift register.
- if self.options['bitorder'] == 'msb-first':
- self.mosidata |= mosi << (ws - 1 - self.bitcount)
- else:
- self.mosidata |= mosi << self.bitcount
+ if self.have_mosi:
+ if self.options['bitorder'] == 'msb-first':
+ self.mosidata |= mosi << (ws - 1 - self.bitcount)
+ else:
+ self.mosidata |= mosi << self.bitcount
- # Receive MISO bit into our shift register.
- if self.options['bitorder'] == 'msb-first':
- self.misodata |= miso << (ws - 1 - self.bitcount)
- else:
- self.misodata |= miso << self.bitcount
+ # Guesstimate the endsample for this bit (can be overridden below).
+ es = self.samplenum
+ if self.bitcount > 0:
+ if self.have_miso:
+ es += self.samplenum - self.misobits[0][1]
+ elif self.have_mosi:
+ es += self.samplenum - self.mosibits[0][1]
+
+ if self.have_miso:
+ self.misobits.insert(0, [miso, self.samplenum, es])
+ if self.have_mosi:
+ self.mosibits.insert(0, [mosi, self.samplenum, es])
+
+ if self.bitcount > 0 and self.have_miso:
+ self.misobits[1][2] = self.samplenum
+ if self.bitcount > 0 and self.have_mosi:
+ self.mosibits[1][2] = self.samplenum
self.bitcount += 1
if self.bitcount != ws:
return
- self.putpw(['DATA', self.mosidata, self.misodata])
- self.putw([0, ['%02X/%02X' % (self.mosidata, self.misodata)]])
- self.putw([1, ['%02X' % self.misodata]])
- self.putw([2, ['%02X' % self.mosidata]])
+ self.putdata()
- if self.cs_was_deasserted_during_data_word:
- self.putw([3, ['CS# was deasserted during this data word!']])
+ # Meta bitrate.
+ elapsed = 1 / float(self.samplerate)
+ elapsed *= (self.samplenum - self.startsample + 1)
+ bitrate = int(1 / elapsed * self.options['wordsize'])
+ self.put(self.startsample, self.samplenum, self.out_bitrate, bitrate)
- # Reset decoder state.
- self.mosidata = 0
- self.misodata = 0
- self.bitcount = 0
+ if self.have_cs and self.cs_was_deasserted:
+ self.putw([4, ['CS# was deasserted during this data word!']])
- # Keep stats for summary.
- self.bytesreceived += 1
+ self.reset_decoder_state()
- def find_clk_edge(self, miso, mosi, sck, cs):
- if self.oldcs != cs:
+ def find_clk_edge(self, miso, mosi, clk, cs):
+ if self.have_cs and self.oldcs != cs:
# Send all CS# pin value changes.
- self.put(self.samplenum, self.samplenum, self.out_proto,
+ self.put(self.samplenum, self.samplenum, self.out_python,
['CS-CHANGE', self.oldcs, cs])
self.oldcs = cs
+ # Reset decoder state when CS# changes (and the CS# pin is used).
+ self.reset_decoder_state()
# Ignore sample if the clock pin hasn't changed.
- if sck == self.oldsck:
+ if clk == self.oldclk:
return
- self.oldsck = sck
+ self.oldclk = clk
# Sample data on rising/falling clock edge (depends on mode).
mode = spi_mode[self.options['cpol'], self.options['cpha']]
- if mode == 0 and sck == 0: # Sample on rising clock edge
+ if mode == 0 and clk == 0: # Sample on rising clock edge
return
- elif mode == 1 and sck == 1: # Sample on falling clock edge
+ elif mode == 1 and clk == 1: # Sample on falling clock edge
return
- elif mode == 2 and sck == 1: # Sample on falling clock edge
+ elif mode == 2 and clk == 1: # Sample on falling clock edge
return
- elif mode == 3 and sck == 0: # Sample on rising clock edge
+ elif mode == 3 and clk == 0: # Sample on rising clock edge
return
# Found the correct clock edge, now get the SPI bit(s).
- self.handle_bit(miso, mosi, sck, cs)
+ self.handle_bit(miso, mosi, clk, cs)
def decode(self, ss, es, data):
- # TODO: Either MISO or MOSI could be optional. CS# is optional.
+ if self.samplerate is None:
+ raise Exception("Cannot decode without samplerate.")
+ # Either MISO or MOSI can be omitted (but not both). CS# is optional.
for (self.samplenum, pins) in data:
# Ignore identical samples early on (for performance reasons).
if self.oldpins == pins:
continue
- self.oldpins, (miso, mosi, sck, cs) = pins, pins
+ self.oldpins, (clk, miso, mosi, cs) = pins, pins
+ self.have_miso = (miso in (0, 1))
+ self.have_mosi = (mosi in (0, 1))
+ self.have_cs = (cs in (0, 1))
+
+ # Either MISO or MOSI (but not both) can be omitted.
+ if not (self.have_miso or self.have_mosi):
+ raise Exception('Either MISO or MOSI (or both) pins required.')
# State machine.
if self.state == 'IDLE':
- self.find_clk_edge(miso, mosi, sck, cs)
+ self.find_clk_edge(miso, mosi, clk, cs)
else:
raise Exception('Invalid state: %s' % self.state)
projects / libsigrokdecode.git / blobdiff