Watchdog and ISP mode

abele_barbieri — Thu, 13 Feb 2025 14:09:32 GMT

Hello,
I'm using LPC51U68 for a customer board, and now I'tring to enter the ISP UART mode by calling from user code the IAP_ReinvokeISP() function.
The LPC answers to "Syncronized" starting messages, and enters in ISP UART mode.
Unfortunately, after the programmed time, the Watchdog resets the board and the application code restart (causing exit from ISP mode).
There is a way to solve/handle this issue?

Thanks

Abele

Re: Watchdog and ISP mode

Habib_MS — Tue, 18 Feb 2025 21:24:30 GMT

Hello @abele_barbieri,
My suspect is that the watchdog is being triggered on the bootloader side. So I will suggest disabling the watchdog and any interruption before calling the ISP reinvoke. However as mentioned in the chapter 17.6.1 called Watchdog mode register "Once the WDEN, WDPROTECT, or WDRESET bits are set they cannot be cleared by software. Both flags are cleared by an external reset or a Watchdog timer reset."
Could you try doing a software reset for the peripheral? The following API should help:
RESET_PeripheralReset(kWWDT_RST_SHIFT_RSTn);

BR
Habib

LPC MicrocontrollersのトピックRe: Watchdog and ISP mode

Watchdog and ISP mode

Re: Watchdog and ISP mode