can: introduce fast bitrate

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

diff --git a/decoders/can/pd.py b/decoders/can/pd.py
index aa49c56beccdf5575bc0d4629904e2b71155b2e0..5d27b28d23105db1096d813ddd782dd986f9611d 100644 (file)
--- a/decoders/can/pd.py
+++ b/decoders/can/pd.py
@@ -37,7 +37,8 @@ class Decoder(srd.Decoder):
         {'id': 'can_rx', 'name': 'CAN RX', 'desc': 'CAN bus line'},
     )
     options = (
-        {'id': 'bitrate', 'desc': 'Bitrate (bits/s)', 'default': 1000000},
+        {'id': 'nominal_bitrate', 'desc': 'Nominal Bitrate (bits/s)', 'default': 1000000},
+        {'id': 'fast_bitrate', 'desc': 'Fast Bitrate (bits/s)', 'default': 2000000},
         {'id': 'sample_point', 'desc': 'Sample point (%)', 'default': 70.0},
     )
     annotations = (
@@ -65,7 +66,6 @@ class Decoder(srd.Decoder):
         ('fields', 'Fields', tuple(range(15))),
         ('warnings', 'Warnings', (16,)),
     )
-    fd = False
 
     def __init__(self):
         self.reset()
@@ -83,7 +83,7 @@ class Decoder(srd.Decoder):
     def metadata(self, key, value):
         if key == srd.SRD_CONF_SAMPLERATE:
             self.samplerate = value
-            self.bit_width = float(self.samplerate) / float(self.options['bitrate'])
+            self.bit_width = float(self.samplerate) / float(self.options['nominal_bitrate'])
             self.sample_point = (self.bit_width / 100.0) * self.options['sample_point']
 
     # Generic helper for CAN bit annotations.
@@ -99,6 +99,10 @@ class Decoder(srd.Decoder):
     def put12(self, data):
         self.putg(self.ss_bit12, self.ss_bit12, data)
 
+    # Single-CAN-bit annotation using the samplenum of CAN bit 32.
+    def put32(self, data):
+        self.putg(self.ss_bit32, self.ss_bit32, data)
+
     # Multi-CAN-bit annotation from self.ss_block to current samplenum.
     def putb(self, data):
         self.putg(self.ss_block, self.samplenum, data)
@@ -112,7 +116,10 @@ class Decoder(srd.Decoder):
         self.last_databit = 999 # Positive value that bitnum+x will never match
         self.ss_block = None
         self.ss_bit12 = None
+        self.ss_bit32 = None
         self.ss_databytebits = []
+        self.fd = False
+        self.rtr = None
 
     # Poor man's clock synchronization. Use signal edges which change to
     # dominant state in rather simple ways. This naive approach is neither
@@ -308,6 +315,8 @@ class Decoder(srd.Decoder):
         # Remember start of EID (see below).
         if bitnum == 14:
             self.ss_block = self.samplenum
+            self.fd = False
+            self.dlc_start = 35
 
         # Bits 14-31: Extended identifier (EID[17..0])
         elif bitnum == 31:
@@ -328,34 +337,58 @@ class Decoder(srd.Decoder):
         # Bit 32: Remote transmission request (RTR) bit
         # Data frame: dominant, remote frame: recessive
         # Remote frames do not contain a data field.
+
+        # Remember start of RTR (see below).
         if bitnum == 32:
-            rtr = 'remote' if can_rx == 1 else 'data'
-            self.putx([8, ['Remote transmission request: %s frame' % rtr,
-                           'RTR: %s frame' % rtr, 'RTR']])
+            self.ss_bit32 = self.samplenum
+            self.rtr = can_rx
+
+            if not self.fd:
+               rtr = 'remote' if can_rx == 1 else 'data'
+               self.putx([8, ['Remote transmission request: %s frame' % rtr,
+                              'RTR: %s frame' % rtr, 'RTR']])
 
         # Bit 33: RB1 (reserved bit)
         elif bitnum == 33:
-            self.putx([7, ['Reserved bit 1: %d' % can_rx,
-                           'RB1: %d' % can_rx, 'RB1']])
+            self.fd = True if can_rx else False
+
+            if self.fd:
+                self.dlc_start = 37
+                self.putx([7, ['Flexible Data Format: %d' % can_rx,
+                               'FDF: %d' % can_rx, 'FDF']])
+
+                self.put32([7, ['Reserved bit 1: %d' % self.rtr,
+                                'RB1: %d' % self.rtr, 'RB1']])
+            else:
+                self.putx([7, ['Reserved bit 1: %d' % can_rx,
+                               'RB1: %d' % can_rx, 'RB1']])
 
         # Bit 34: RB0 (reserved bit)
         elif bitnum == 34:
             self.putx([7, ['Reserved bit 0: %d' % can_rx,
                            'RB0: %d' % can_rx, 'RB0']])
 
+        elif bitnum == 35 and self.fd:
+            self.putx([7, ['Bit rate switch: %d' % can_rx,
+                           'BRS: %d' % can_rx, 'BRS']])
+
+        elif bitnum == 36 and self.fd:
+            self.putx([7, ['Error state indicator: %d' % can_rx,
+                           'ESI: %d' % can_rx, 'ESI']])
+
         # Remember start of DLC (see below).
-        elif bitnum == 35:
+        elif bitnum == self.dlc_start:
             self.ss_block = self.samplenum
 
         # Bits 35-38: Data length code (DLC), in number of bytes (0-8).
-        elif bitnum == 38:
-            self.dlc = int(''.join(str(d) for d in self.bits[35:38 + 1]), 2)
+        elif bitnum == self.dlc_start + 3:
+            self.dlc = int(''.join(str(d) for d in self.bits[self.dlc_start:self.dlc_start + 4]), 2)
             self.putb([10, ['Data length code: %d' % self.dlc,
                             'DLC: %d' % self.dlc, 'DLC']])
-            self.last_databit = 38 + (self.dlc2len(self.dlc) * 8)
+            self.last_databit = self.dlc_start + 3 + (self.dlc2len(self.dlc) * 8)
 
         # Remember all databyte bits, except the very last one.
-        elif bitnum in range(39, self.last_databit):
+        elif bitnum in range(self.dlc_start + 4, self.last_databit):
             self.ss_databytebits.append(self.samplenum)
 
         # Bits 39-X: Data field (0-8 bytes, depending on DLC)
@@ -363,7 +396,7 @@ class Decoder(srd.Decoder):
         elif bitnum == self.last_databit:
             self.ss_databytebits.append(self.samplenum) # Last databyte bit.
             for i in range(self.dlc2len(self.dlc)):
-                x = 38 + (8 * i) + 1
+                x = self.dlc_start + 4 + (8 * i)
                 b = int(''.join(str(d) for d in self.bits[x:x + 8]), 2)
                 ss = self.ss_databytebits[i * 8]
                 es = self.ss_databytebits[((i + 1) * 8) - 1]