How to Enable SWD Debug on the FRDM-IMX91 and FRDM-IMX93 Boards

[Aghogho]

In case anyone is having issues with enabling/using SWD debug on the new FRDM-IMX91 and FRDM-IMX93 boards, I found out that you have to remove resistors R3017 & R3018 to have SWD debug enabled. This is because the SWD lines (JTAG_TMS/JTAG_TCK) are connected to the UART5 RTS/CTS lines of the WIFI/BLE module on the board. Thus, you will have to remove these resistors if you want to enable/use SWD debug with these boards. If you do not remove thses resistors, you cannot debug the boards using the SWD port. It took me some time to realize this after being unable to debug my board. I am just posting this as a way to help others.

[June_Lu]

Thanks for sharing, it's same as me.

Disconnect the R3017 & R3018.

Connect 4 signals below

https://kb.segger.com/20-pin_J-Link_Connector

FRDM-IMX93_P4	J-Link / J-Trace SWD pinout(20pin)
1-SWCLK	J9-SWCLK
2-SWDIO	J7-SWDIO
3-GND	J6-GND

FRDM-IMX93_Q23	J-Link / J-Trace SWD pinout(20pin)
1-VDD_1V8	J1-Vtref

SW1[4:1]=1011.

Then, follow the AN14120 to do the debug.

Thanks

[Aghogho]

For my case, I used the Segger j-link as my debug probe. I connected the JTAG_TCK & JTAG_TMS pins of the probe to the SWCLK and SWDIO pins of the debug port on the FRDM-IMX93 or FRDM-IMX91. Also, connect the ground pins of the j_link to the ground pin of the debug port. Then you have to configure the probe for a fixed 1.8V reference. If you are using an older j-link (less than v13) you will have to find a 1.8V source to connect your VREF pin of the J-Link.

[June_Lu]

Thanks for the sharing, would you share the signals you connect between the FRDM-IMX93 and debug tool(JLink) when you debug the FRDM-IMX93?

Thanks