CMSIS-DAP: SWD/JTAG Communication Failure after working previously

[MISO_27]

I am using the MIMXRT1170-EVK together with the Keil uVision5 IDE and MCUXpresso Config Tools and was initially able to successfully program the board (e.g. with example projects). 

After developing a small program using the LPSPI peripheral in transfer mode and running it in debug mode, debugging stopped with an error message (i can't recall what it said). After that, connection to the board via the CMSIS-DAP debugger is not possible anymore (error message SWD/JTAG Communication Failure). For debug setting see attached picture. I already tried different max clock settings. I didn't modify any jumpers or switches compared to the previously working default configuration.

I also tried to connect to the board via MCUXpresso IDE but it didn't work either.

Can someone help me recover the board?

[MISO_27 · Accepted solution]

The solution is to use the serial downloader ("SDP Mode"; SW1: 0-0-0-1; SW2: all 0s), erase data in QSPI flash and program a example project. After a power reset the board can be debugged in default configuration again.

This document details the procedure: https://community.nxp.com/pwmxy87654/attachments/pwmxy87654/mcux-blogs/123/1/RT1170_BriefOverview_v1...