Add a CFP decoder.

[libsigrokdecode.git] / decoders / parallel / pd.py

diff --git a/decoders/parallel/pd.py b/decoders/parallel/pd.py
index 1c3435c23943d6a6f702dbd56a97987a894f7ecf..0e81344855a204c2407cc285f6102e2f3dc14943 100644 (file)
--- a/decoders/parallel/pd.py
+++ b/decoders/parallel/pd.py
@@ -79,7 +79,8 @@ class Decoder(srd.Decoder):
     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')},
     )
@@ -87,6 +88,10 @@ class Decoder(srd.Decoder):
         ('items', 'Items'),
         ('words', 'Words'),
     )
+    annotation_rows = (
+        ('items', 'Items', (0,)),
+        ('words', 'Words', (1,)),
+    )
 
     def __init__(self):
         self.reset()
@@ -95,6 +100,8 @@ class Decoder(srd.Decoder):
         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):
@@ -114,11 +121,19 @@ class Decoder(srd.Decoder):
         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([1, [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
@@ -128,30 +143,25 @@ class Decoder(srd.Decoder):
             # 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([0, [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):
@@ -167,7 +177,6 @@ class Decoder(srd.Decoder):
         if not has_channels:
             raise ChannelError('At least one channel has to be supplied.')
         max_connected = max(has_channels)
-        idx_strip = max_connected + 1
 
         # Determine .wait() conditions, depending on the presence of a
         # clock signal. Either inspect samples on the configured edge of
@@ -179,11 +188,24 @@ class Decoder(srd.Decoder):
         else:
             conds = [{idx: 'e'} for idx in has_channels]
 
+        # 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.
+        idx_strip = max_connected + 1
+        num_item_bits = idx_strip - 1
+        num_word_items = self.options['wordsize']
+        num_word_bits = num_item_bits * num_word_items
+        num_digits = (num_item_bits + 3) // 4
+        self.fmt_item = "{{:0{}x}}".format(num_digits)
+        num_digits = (num_word_bits + 3) // 4
+        self.fmt_word = "{{:0{}x}}".format(num_digits)
+
         # 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))
+            item = bitpack(bits[1:idx_strip])
+            self.handle_bits(item, num_item_bits)