can we use CoreDebug->DHCSR to check if JLink is connected with Monitor Mode Debugging enabled?

[Min-Ching Ho]

Hi,

    I need a way to dynamically disable watchdog when I do MMD debugging. I found the old trick, check bit 0 on CoreDebug->DHCSR, does not work any more in MMD. Is that expected? Is there any other way to let the device check if JLink is connected?

Thank you,

Min-Ching

[awneil]

MMD is a Segger thing - not specific to Nordic - so you'd have to ask Segger for details.

https://forum.segger.com/

When you set up MMD, you add a little code to your project - so take a look at that to see if it gives any clues, or provides anything your could "hook" ...

The 'H' in DHCSR is for "Halting" - so probably not relevant to Monitor (ie, non-Halting) mode ...

Looking at the Cortex-M4 Technical Reference Manual:

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0439b/BABJHEIG.html

it seems like the DEMCR might be the place to look ?

There is a MON_EN bit ...

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0337e/CEGHJDCF.html

[Min-Ching Ho]

Hi awneil,

    I tired this. the bit was not set when I inspect it when JLink is connected. I also checked all other bits. I don't think any of these bits can be used for the purpose. I only see TRCENA set which is set in the code. 

Thank you for the suggestion.

Min-Ching Ho

[awneil]

Oh well - it was just speculation.

As I said, for a definitive answer you will have to ask Segger.