diff options
| -rw-r--r-- | decoders/jtag_stm32/pd.py | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/decoders/jtag_stm32/pd.py b/decoders/jtag_stm32/pd.py index f2dd3c7..51c910d 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 @@ -183,7 +183,11 @@ class Decoder(srd.Decoder): self.ss, self.es = ss, es - # self.put(self.ss, self.es, self.out_ann, [0, [cmd + ' / ' + val]]) + # 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 +195,10 @@ 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': |