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LPC4357: could not stop Cortex-M device

Former Member

I have available a fine EVB from Element14 with LPC4357-uC and 32 MB SDRAM,

using Keils uVision4 and Ulink2

Unfortunatly, I have managed to look the device with problematic code,

flashing using ulink2 is no more possible

Reducing the clock for jtag or SW was not successfull, the problem remains.

Is there another methode available to get access again ?

The basic problem is that this EVB always boots from internal flash if there is code stored,

no matter what boot-options are selected by dip-switches.

  • 0

    Try some alternative settings in the Keil debugger setup window. Often "connect under reset" can get you out of this hole..

     

    I don't use the NXP processors - ST ARM based micros all include  a bootloader which can be accessed by setting the mode pins to the correct state and applying power - usually a whole chip erase will fix things.

     

    I might be able to help better if you can tell me the exact part number or Farnell stock code for your board.

     

    MK

  • 0 in reply to michaelkellett

    Using "connect under reset" fails in geting a connection at all.

     

    I have available now a 2nd EVB using external flash only while developing

    and switch to internal flash ONLY in case the code is running.

    Additionaly, there is some delay included in startup, but is not verified if this really helps.

     

    For the 2nd EVB I faced the same problem but was able to get connection again

    using SW with 500 KHz, connect with pre-reset using VECTRESET

    and all other options disabled ( like caching eg ).

     

    For the 1st board the problem remains, nothing helped so far

    to get out of this trap.