Issue with Debugging DA14531 After Programming OTP

Question

Hi Everyone,

I'm using the DA14531. After I programmed the code into the OTP and set the flags to "YES" for the chip to boot from the OTP, the device can boot from the OTP. However, when I try to debug on Keil, it shows the error "No Cortex-M SW device Found." When I use SmartSnippets Toolbox to connect, it also cannot detect the device. I encounter this issue on both the custom board and the Devkit (Daughter board, mother board). Does anyone have any suggestions regarding this issue?

Thanks.

OV_Renesas · Answer

Hi Tung, Thank you for posting your question online. It seems you have disabled the SWD interface in your code. You have either directly disabled the SWD interface via SW or the device entered into Sleep mode (where SWD is by default disabled) and it cannot wake-up. You could try to access the device via 1-WIre UART in order to load a new firmware into the SRAM where the SWD interface will be enabled. However, if you have programmed the OTP memory, you can not erase it and the SWD interface will continue to be disabled even if you enable it momentarily via the SRAM. Please proceed to OTP programming after you have fully tested and verified your firmware. Best Regards, OV_Renesas