LPC MicrocontrollersのトピックRe: LPC4357: could not stop Cortex-M device

LPC4357: could not stop Cortex-M device

hartmutmeyer — Sun, 14 Aug 2016 11:16:26 GMT

I have managed somehow to set my Cortex-M-device in a state where flashing is no more possible ( using uVision4 and ulink2 ).

It is for sure that this has something to do with the last code I have flashed :smileysad:

There are already several postings about this topic in the web, so this is nothing new.

I have tried the known ways like reducing the clock-speed, try different reset-options eg, but all fails.

I faced this problem already but was able to connect later again, but now it looks like matters are much more difficult.

Obviously, the code has direct impact on the "strength" of this issue, there may be a way out or not.

I have read about a solution by adding some delay during startup, but at least for this board this seems to be to late,

therefore a new one is on it's way.

For future versions I will probably use external flash only + delay inside startup-code and switch to internal flash only in case

the code is running.

This avoids booting always from internal flash by automatic on the EVB used, no matter what boot-options are set :smileyhappy:

Re: LPC4357: could not stop Cortex-M device

lpcxpresso_supp — Tue, 16 Aug 2016 07:50:08 GMT

Try booting the board into ISP mode. This should then allow the debugger to take control, or for you to connect over UART using a tool like Flashmagic to erase the flash (Flash Magic - Welcome ).

Although the following FAQ is targeted at LPCXpresso IDE, the information about ISP booting is valid regardless of toolchain:Regaining debug access to target MCU

Regards,

LPCXpresso Support

Re: LPC4357: could not stop Cortex-M device

hartmutmeyer — Tue, 16 Aug 2016 15:52:58 GMT

The board in use do neither has COM nor Ethernet-ports, only USB and the standard 20-pin-debug-port.

USB is not set up, it looks like using Ulink2 is the only way to get access.

I was using Flash Magic but failed to establish a connection via Ulink2 only.

Now I have available a 2nd EVB, booting is done now using external flash only.

In case there should go something wrong again, I could switch to internal flash using a working program

to get access any time again.

For the first EVB I will try to get access again from time to time...