lpc: Add annotation helper method.

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

diff --git a/decoders/usb_signalling/pd.py b/decoders/usb_signalling/pd.py
index 44aaaca1d8135d487788a90f9acd47edc28e5545..d2a1e8add21a7fd0ff9f7b0b0fc254065db579cd 100644 (file)
--- a/decoders/usb_signalling/pd.py
+++ b/decoders/usb_signalling/pd.py
@@ -23,6 +23,27 @@
 
 import sigrokdecode as srd
 
+'''
+Protocol output format:
+
+Packet:
+[<ptype>, <pdata>]
+
+<ptype>, <pdata>:
+ - 'SOP', None
+ - 'SYM', <sym>
+ - 'BIT', <bit>
+ - 'STUFF BIT', None
+ - 'EOP', None
+
+<sym>:
+ - 'J', 'K', 'SE0', or 'SE1'
+
+<bit>:
+ - 0 or 1
+ - Note: Symbols like SE0, SE1, and the J that's part of EOP don't yield 'BIT'.
+'''
+
 # Low-/full-speed symbols.
 # Note: Low-speed J and K are inverted compared to the full-speed J and K!
 symbols = {
@@ -65,19 +86,18 @@ class Decoder(srd.Decoder):
         'signalling': ['Signalling', 'full-speed'],
     }
     annotations = [
-        ['symbol', 'Symbol'],
+        ['sym', 'Symbol'],
         ['sop', 'Start of packet (SOP)'],
         ['eop', 'End of packet (EOP)'],
         ['bit', 'Bit'],
         ['stuffbit', 'Stuff bit'],
-        ['packet', 'Packet'],
     ]
 
     def __init__(self):
         self.oldsym = 'J' # The "idle" state is J.
-        self.ss_sop = -1
+        self.ss_sop = None
+        self.ss_block = None
         self.samplenum = 0
-        self.packet = ''
         self.syms = []
         self.bitrate = None
         self.bitwidth = None
@@ -92,6 +112,7 @@ class Decoder(srd.Decoder):
         self.out_ann = self.add(srd.OUTPUT_ANN, 'usb_signalling')
         self.bitrate = bitrates[self.options['signalling']]
         self.bitwidth = float(metadata['samplerate']) / float(self.bitrate)
+        self.halfbit = int(self.bitwidth / 2)
 
     def report(self):
         pass
@@ -102,13 +123,21 @@ class Decoder(srd.Decoder):
     def putx(self, data):
         self.put(self.samplenum, self.samplenum, self.out_ann, data)
 
+    def putpm(self, data):
+        s, h = self.samplenum, self.halfbit
+        self.put(self.ss_block - h, s + h, self.out_proto, data)
+
+    def putm(self, data):
+        s, h = self.samplenum, self.halfbit
+        self.put(self.ss_block - h, s + h, self.out_ann, data)
+
     def putpb(self, data):
-        s, halfbit = self.samplenum, int(self.bitwidth / 2)
-        self.put(s - halfbit, s + halfbit, self.out_proto, data)
+        s, h = self.samplenum, self.halfbit
+        self.put(s - h, s + h, self.out_proto, data)
 
     def putb(self, data):
-        s, halfbit = self.samplenum, int(self.bitwidth / 2)
-        self.put(s - halfbit, s + halfbit, self.out_ann, data)
+        s, h = self.samplenum, self.halfbit
+        self.put(s - h, s + h, self.out_ann, data)
 
     def set_new_target_samplenum(self):
         bitpos = self.ss_sop + (self.bitwidth / 2)
@@ -128,13 +157,14 @@ class Decoder(srd.Decoder):
 
     def handle_bit(self, sym, b):
         if self.consecutive_ones == 6 and b == '0':
-            # Stuff bit. Don't add to the packet, reset self.consecutive_ones.
+            # Stuff bit.
+            self.putpb(['STUFF BIT', None])
             self.putb([4, ['SB: %s/%s' % (sym, b)]])
             self.consecutive_ones = 0
         else:
-            # Normal bit. Add it to the packet, update self.consecutive_ones.
+            # Normal bit (not a stuff bit).
+            self.putpb(['BIT', b])
             self.putb([3, ['%s/%s' % (sym, b)]])
-            self.packet += b
             if b == '1':
                 self.consecutive_ones += 1
             else:
@@ -149,16 +179,17 @@ class Decoder(srd.Decoder):
         self.set_new_target_samplenum()
         self.oldsym = sym
         if self.syms[-2:] == ['SE0', 'J']:
-            # Got an EOP, i.e. we now have a full packet.
-            self.putpb(['PACKET', self.packet])
-            self.putb([5, ['PACKET: %s' % self.packet]])
-            self.bitnum, self.packet, self.syms, self.state = 0, '', [], 'IDLE'
+            # Got an EOP.
+            self.putpm(['EOP', None])
+            self.putm([2, ['EOP']])
+            self.bitnum, self.syms, self.state = 0, [], 'IDLE'
             self.consecutive_ones = 0
 
     def get_bit(self, sym):
         if sym == 'SE0':
             # Start of an EOP. Change state, run get_eop() for this bit.
             self.state = 'GET EOP'
+            self.ss_block = self.samplenum
             self.get_eop(sym)
             return
         self.syms.append(sym)