embeded/ARM2012.03.23 10:16
리셋이 안된다고 배째는데
아무튼 TAP 값은 맞으니까 칩 종류를 받아오는 것일테고 -_-
의심이 가는건 nTRST 연결 상태?

  • nSRST bi-directional (open collector)
    This pin serves two purposes. It can be used by the adapter to reset the target board, which is most useful during remote debugging. Furthermore, the adapter is able to detect that the reset is triggered on the target by another event, like pressing the reset button or a watchdog timeout.
  • nTRST from adapter to target
    According to the JTAG standard, the TAP controller is reset to a known state by keeping TMS high for five consecutive TCK cycles. However, some targets have problems with this sequence and thus require a hardware reset, which is marked optional in the IEEE specification. On several chips, like the AT91R40008 used on Ethernut 3, nSRST and nTRST are internally tied together. The disadvantage with this design is, that you can’t trigger a breakpoint immediately after a target hardware reset. If this signal is not used on the target, it is recommended to pull up this line with 10kOhm.
[링크 : http://www.jtagprogrammer.com/jtag-signals/]
2010/06/26 - [embeded/ARM] - ARM JTAG - Wiggler 14pin , 20pin pinout

arm 설명에서는 반드시있을 이유는 없지만, 하는걸 권장한다고 한다.
2012/03/23 - [embeded/ARM] - KEIL MDK(ARM)에 H-JTAG 사용하기

[링크 : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka3887.html]
    [링크 : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka3894.html] nTRST 
    [링크 : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka3895.html] nSRST

nTRST는 Target ReSeT 인거 같은데
nSRST는 무슨 리셋이려나? 
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Posted by 구차니
TAG ,

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