Debugging a K64 application in Low-Level-Stop mode

[fcw]

I'm integrating a new piece of code for a Kinetis K64 which switches to low-level stop mode when the controller has nothing to do. The mode switches are working fine: Supply current drops to ~zero when in stop, jumps back to a few 10s of mA when active.

The issue is debug. Development is done with an IAR IDE using a Segger pod packaged with the IDE at the time we licensed it. Quick Run-Stop-Run transitions work fine. Dwelling in Stop (where I'm not attempting to do any debugger actions) causes a controller reset.

I've used the Segger release provided with the IDE, an ancient 6.30 and the current 8.18. No joy with either one.

Has anyone come up with a way around this?

[Celeste_Liu · Accepted solution]

Hello @fcw ,

Thanks for your post.

About low power mode debug, you can refer to the section "9.14 Debug in Low Power Modes" and section "9.14.1 Debug Module State in Low Power Modes" of the K64 Reference manual. 

From the above content, it can be seen that normal debugging under VLPS/VLLSx is not possible.

However, you can mantain the debugger on so when the device will wake up you can resume the code analysis, please refer to Attaching to a Running Target with Segger J-Link, GDB and Eclipse | MCU on Eclipse.

Hope it can help you.

BRs,

Celeste

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[fcw]

Hi, Celeste,

Thank you for the reply. I "Accepted the Solution" but a note I wrote didn't make the trip. Sorry if this is a duplicate: Section 9 and other docs all discussed JTAG, not SWD. Switched the debug connection to SWD and no resets and the debugger resumes operation when the controller switches out of LLS.