word <worditemcount> is 7, and so on.
'''
-def channel_list(num_channels):
- l = [{'id': 'clk', 'name': 'CLK', 'desc': 'Clock line'}]
- for i in range(num_channels):
- d = {'id': 'd%d' % i, 'name': 'D%d' % i, 'desc': 'Data line %d' % i}
- l.append(d)
- return tuple(l)
+NUM_CHANNELS = 8
+
+class Pin:
+ CLOCK = 0
+ DATA_0 = CLOCK + 1
+ DATA_N = DATA_0 + NUM_CHANNELS
+
+class Ann:
+ ITEM, WORD = range(2)
class ChannelError(Exception):
pass
-NUM_CHANNELS = 8
-
class Decoder(srd.Decoder):
api_version = 3
id = 'parallel'
license = 'gplv2+'
inputs = ['logic']
outputs = ['parallel']
- optional_channels = channel_list(NUM_CHANNELS)
+ tags = ['Util']
+ optional_channels = tuple(
+ [{'id': 'clk', 'name': 'CLK', 'desc': 'Clock line'}] +
+ [
+ {'id': 'd%d' % i, 'name': 'D%d' % i, 'desc': 'Data line %d' % i}
+ for i in range(NUM_CHANNELS)
+ ]
+ )
options = (
{'id': 'clock_edge', 'desc': 'Clock edge to sample on',
'default': 'rising', 'values': ('rising', 'falling')},
- {'id': 'wordsize', 'desc': 'Data wordsize', 'default': 1},
+ {'id': 'wordsize', 'desc': 'Data wordsize (# bus cycles)',
+ 'default': 0},
{'id': 'endianness', 'desc': 'Data endianness',
'default': 'little', 'values': ('little', 'big')},
)
annotations = (
- ('items', 'Items'),
- ('words', 'Words'),
+ ('item', 'Item'),
+ ('word', 'Word'),
+ )
+ annotation_rows = (
+ ('items', 'Items', (Ann.ITEM,)),
+ ('words', 'Words', (Ann.WORD,)),
)
def __init__(self):
self.items = []
self.saved_item = None
self.ss_item = self.es_item = None
+ self.saved_word = None
+ self.ss_word = self.es_word = None
self.first = True
def start(self):
self.put(self.ss_word, self.es_word, self.out_ann, data)
def handle_bits(self, item, used_pins):
- # Save the item, and its sample number if it's the first part of a word.
- if not self.items:
- self.ss_word = self.samplenum
- self.items.append(item)
+ # If a word was previously accumulated, then emit its annotation
+ # now after its end samplenumber became available.
+ if self.saved_word is not None:
+ if self.options['wordsize'] > 0:
+ self.es_word = self.samplenum
+ self.putw([Ann.WORD, [self.fmt_word.format(self.saved_word)]])
+ self.putpw(['WORD', self.saved_word])
+ self.saved_word = None
+
+ # Defer annotations for individual items until the next sample
+ # is taken, and the previous sample's end samplenumber has
+ # become available.
if self.first:
# Save the start sample and item for later (no output yet).
self.ss_item = self.samplenum
# Output the saved item (from the last CLK edge to the current).
self.es_item = self.samplenum
self.putpb(['ITEM', self.saved_item])
- self.putb([0, ['%X' % self.saved_item]])
+ self.putb([Ann.ITEM, [self.fmt_item.format(self.saved_item)]])
self.ss_item = self.samplenum
self.saved_item = item
- # Get as many items as the configured wordsize says.
+ # Get as many items as the configured wordsize specifies.
+ if not self.items:
+ self.ss_word = self.samplenum
+ self.items.append(item)
ws = self.options['wordsize']
if len(self.items) < ws:
return
- # Output annotations/python for a word (a collection of items).
- # NOTE that this feature is currently not effective. The emission
- # of Python annotations is commented out.
+ # Collect words and prepare annotation details, but defer emission
+ # until the end samplenumber becomes available.
endian = self.options['endianness']
- if endian == 'little':
+ if endian == 'big':
self.items.reverse()
- word = 0
- for i in range(ws):
- word |= self.items[i] << (i * used_pins)
-
- self.es_word = self.samplenum
- # self.putpw(['WORD', word])
- # self.putw([1, ['%X' % word]])
- self.ss_word = self.samplenum
-
+ word = sum([self.items[i] << (i * used_pins) for i in range(ws)])
+ self.saved_word = word
self.items = []
def decode(self):
# Determine which (optional) channels have input data. Insist in
# a non-empty input data set. Cope with sparse connection maps.
# Store enough state to later "compress" sampled input data.
- max_possible = len(self.optional_channels)
- idx_channels = [
+ data_indices = [
idx if self.has_channel(idx) else None
- for idx in range(max_possible)
+ for idx in range(Pin.DATA_0, Pin.DATA_N)
]
- has_channels = [idx for idx in idx_channels if idx is not None]
- if not has_channels:
- raise ChannelError('At least one channel has to be supplied.')
- max_connected = max(has_channels)
- idx_strip = max_connected + 1
+ has_data = [idx for idx in data_indices if idx is not None]
+ if not has_data:
+ raise ChannelError('Need at least one data channel.')
+ max_connected = max(has_data)
+
+ # Pre-determine which input data to strip off, the width of
+ # individual items and multiplexed words, as well as format
+ # strings here. This simplifies call sites which run in tight
+ # loops later.
+ upper_data_bound = max_connected + 1
+ num_item_bits = upper_data_bound - Pin.DATA_0
+ num_word_items = self.options['wordsize']
+ num_word_bits = num_item_bits * num_word_items
+ num_digits = (num_item_bits + 4 - 1) // 4
+ self.fmt_item = "{{:0{}x}}".format(num_digits)
+ num_digits = (num_word_bits + 4 - 1) // 4
+ self.fmt_word = "{{:0{}x}}".format(num_digits)
# Determine .wait() conditions, depending on the presence of a
# clock signal. Either inspect samples on the configured edge of
# the clock, or inspect samples upon ANY edge of ANY of the pins
# which provide input data.
- if self.has_channel(0):
+ has_clock = self.has_channel(Pin.CLOCK)
+ if has_clock:
edge = self.options['clock_edge'][0]
- conds = {0: edge}
+ conds = [{Pin.CLOCK: edge}]
else:
- conds = [{idx: 'e'} for idx in has_channels]
+ conds = [{idx: 'e'} for idx in has_data]
# Keep processing the input stream. Assume "always zero" for
# not-connected input lines. Pass data bits (all inputs except
# clock) to the handle_bits() method.
while True:
pins = self.wait(conds)
- bits = [0 if idx is None else pins[idx] for idx in idx_channels]
- bits = bits[1:idx_strip]
- self.handle_bits(bitpack(bits), len(bits))
+ data_bits = [0 if idx is None else pins[idx] for idx in data_indices]
+ data_bits = data_bits[:num_item_bits]
+ item = bitpack(data_bits)
+ self.handle_bits(item, num_item_bits)
projects / libsigrokdecode.git / blobdiff