'''
OUTPUT_PYTHON format:
-SPI packet:
-[<cmd>, <data1>, <data2>]
+Packet:
+[<ptype>, <data1>, <data2>]
-Commands:
- - 'DATA': <data1> contains the MISO data, <data2> contains the MOSI data.
+<ptype>:
+ - 'DATA': <data1> contains the MOSI data, <data2> contains the MISO 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.
+ channel was not supplied.
+ - 'BITS': <data1>/<data2> contain a list of bit values in this MOSI/MISO 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]
(1, 1): 3, # Mode 3
}
+class SamplerateError(Exception):
+ pass
+
+class ChannelError(Exception):
+ pass
+
class Decoder(srd.Decoder):
- api_version = 1
+ api_version = 2
id = 'spi'
name = 'SPI'
longname = 'Serial Peripheral Interface'
license = 'gplv2+'
inputs = ['logic']
outputs = ['spi']
- probes = [
+ channels = (
{'id': 'clk', 'name': 'CLK', 'desc': 'Clock'},
- ]
- optional_probes = [
+ )
+ optional_channels = (
{'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'},
- ]
- 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'],
- }
- annotations = [
- ['miso-data', 'MISO SPI data'],
- ['mosi-data', 'MOSI SPI data'],
- ['warnings', 'Human-readable warnings'],
- ]
+ )
+ 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',
+ 'default': 'msb-first', 'values': ('msb-first', 'lsb-first')},
+ {'id': 'wordsize', 'desc': 'Word size', 'default': 8},
+ )
+ annotations = (
+ ('miso-data', 'MISO data'),
+ ('mosi-data', 'MOSI data'),
+ ('miso-bits', 'MISO bits'),
+ ('mosi-bits', 'MOSI bits'),
+ ('warnings', 'Human-readable warnings'),
+ )
annotation_rows = (
- ('miso', 'MISO', (0,)),
- ('mosi', 'MOSI', (1,)),
- ('other', 'Other', (2,)),
+ ('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.samplerate = None
self.oldclk = 1
self.bitcount = 0
- self.mosidata = 0
- self.misodata = 0
- self.startsample = -1
+ self.misodata = self.mosidata = 0
+ self.misobits = []
+ self.mosibits = []
+ self.ss_block = -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 = None
- self.have_miso = None
- self.have_mosi = None
- self.state = 'IDLE'
+ self.have_cs = self.have_miso = self.have_mosi = None
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.out_bitrate = self.register(srd.OUTPUT_META,
meta=(int, 'Bitrate', 'Bitrate during transfers'))
- def putpw(self, data):
- self.put(self.startsample, self.samplenum, self.out_python, data)
-
def putw(self, data):
- self.put(self.startsample, self.samplenum, self.out_ann, data)
+ self.put(self.ss_block, self.samplenum, self.out_ann, data)
+
+ 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, save its sample number.
+ # If this is the first bit of a dataword, save its sample number.
if self.bitcount == 0:
- self.startsample = self.samplenum
+ self.ss_block = self.samplenum
+ self.cs_was_deasserted = False
if self.have_cs:
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 = (cs == 1) if active_low else (cs == 0)
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.have_mosi:
if self.options['bitorder'] == 'msb-first':
else:
self.mosidata |= mosi << self.bitcount
- # Receive MISO bit into our shift register.
+ # 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:
- if self.options['bitorder'] == 'msb-first':
- self.misodata |= miso << (ws - 1 - self.bitcount)
- else:
- self.misodata |= miso << self.bitcount
+ 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
- si = self.mosidata if self.have_mosi else None
- so = self.misodata if self.have_miso else None
-
- # Pass MOSI and MISO to the next PD up the stack.
- self.putpw(['DATA', si, so])
-
- # Annotations.
- if self.have_miso:
- self.putw([0, ['%02X' % self.misodata]])
- if self.have_mosi:
- self.putw([1, ['%02X' % self.mosidata]])
+ self.putdata()
# Meta bitrate.
- elapsed = 1 / float(self.samplerate) * (self.samplenum - self.startsample + 1)
+ elapsed = 1 / float(self.samplerate)
+ elapsed *= (self.samplenum - self.ss_block + 1)
bitrate = int(1 / elapsed * self.options['wordsize'])
- self.put(self.startsample, self.samplenum, self.out_bitrate, bitrate)
+ self.put(self.ss_block, self.samplenum, self.out_bitrate, bitrate)
- if self.have_cs and self.cs_was_deasserted_during_data_word:
- self.putw([2, ['CS# was deasserted during this data word!']])
+ if self.have_cs and self.cs_was_deasserted:
+ self.putw([4, ['CS# was deasserted during this data word!']])
- # Reset decoder state.
- self.misodata = 0 if self.have_miso else None
- self.mosidata = 0 if self.have_mosi else None
- self.bitcount = 0
+ self.reset_decoder_state()
def find_clk_edge(self, miso, mosi, clk, cs):
if self.have_cs and self.oldcs != cs:
['CS-CHANGE', self.oldcs, cs])
self.oldcs = cs
# Reset decoder state when CS# changes (and the CS# pin is used).
- self.misodata = 0 if self.have_miso else None
- self.mosidata = 0 if self.have_mosi else None
- self.bitcount = 0
+ self.reset_decoder_state()
# Ignore sample if the clock pin hasn't changed.
if clk == self.oldclk:
self.handle_bit(miso, mosi, clk, cs)
def decode(self, ss, es, data):
- if self.samplerate is None:
- raise Exception("Cannot decode without samplerate.")
+ if not self.samplerate:
+ raise SamplerateError('Cannot decode without samplerate.')
# Either MISO or MOSI can be omitted (but not both). CS# is optional.
for (self.samplenum, pins) in data:
self.have_mosi = (mosi in (0, 1))
self.have_cs = (cs in (0, 1))
- # State machine.
- if self.state == 'IDLE':
- self.find_clk_edge(miso, mosi, clk, cs)
- else:
- raise Exception('Invalid state: %s' % self.state)
+ # Either MISO or MOSI (but not both) can be omitted.
+ if not (self.have_miso or self.have_mosi):
+ raise ChannelError('Either MISO or MOSI (or both) pins required.')
+ self.find_clk_edge(miso, mosi, clk, cs)