X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=decoders%2Fjtag_stm32%2Fpd.py;h=10a098fa4276660b78bc1bec04e3252db8e9ca72;hb=a4dd548f5332453cef7442e453eef99343bdc5fb;hp=f2dd3c7726dfce97e6a5040204be57afac2b8547;hpb=35b380b1156434b73d4a976c68f5ab3604c8510a;p=libsigrokdecode.git

diff --git a/decoders/jtag_stm32/pd.py b/decoders/jtag_stm32/pd.py
index f2dd3c7..10a098f 100644
--- a/decoders/jtag_stm32/pd.py
+++ b/decoders/jtag_stm32/pd.py
@@ -1,7 +1,7 @@
 ##
 ## This file is part of the libsigrokdecode project.
 ##
-## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+## Copyright (C) 2012-2015 Uwe Hermann <uwe@hermann-uwe.de>
 ##
 ## This program is free software; you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -133,7 +133,7 @@ class Decoder(srd.Decoder):
 
     def __init__(self, **kwargs):
         self.state = 'IDLE'
-        # self.state = 'BYPASS'
+        self.samplenums = None
 
     def start(self):
         self.out_ann = self.register(srd.OUTPUT_ANN)
@@ -178,12 +178,20 @@ class Decoder(srd.Decoder):
                  [0, ['Unknown instruction: ' % bits]]) # TODO
 
     def decode(self, ss, es, data):
-        # Assumption: The right-most char in the 'val' bitstring is the LSB.
         cmd, val = data
 
         self.ss, self.es = ss, es
 
-        # self.put(self.ss, self.es, self.out_ann, [0, [cmd + ' / ' + val]])
+        if cmd != 'NEW STATE':
+            val, self.samplenums = val
+
+            # The right-most char in the 'val' bitstring is the LSB.
+
+            # The STM32F10xxx has two serially connected JTAG TAPs, the
+            # boundary scan tap (5 bits) and the Cortex-M3 TAP (4 bits).
+            # See UM 31.5 "STM32F10xxx JTAG TAP connection" for details.
+            # Due to this, we need to ignore the last bit of each data shift.
+            val = val[:-1]
 
         # State machine
         if self.state == 'IDLE':
@@ -191,9 +199,10 @@ class Decoder(srd.Decoder):
             if cmd != 'IR TDI':
                 return
             # Switch to the state named after the instruction, or 'UNKNOWN'.
-            # Ignore bits other than IR[3:0]. While the IR register is only
-            # 4 bits in size, some programs (e.g. OpenOCD) might fill in a
-            # few more (dummy) bits. OpenOCD makes IR at least 8 bits long.
+            # The STM32F10xxx has two serially connected JTAG TAPs, the
+            # boundary scan tap (5 bits) and the Cortex-M3 TAP (4 bits).
+            # See UM 31.5 "STM32F10xxx JTAG TAP connection" for details.
+            # Currently we only care about the latter and use IR[3:0].
             self.state = ir.get(val[-4:], ['UNKNOWN', 0])[0]
             self.put(self.ss, self.es, self.out_ann, [0, ['IR: ' + self.state]])
         elif self.state == 'BYPASS':