LPC4078 Watchdog timer always resets

billbrown — Thu, 04 Aug 2016 19:35:24 GMT

Its always the simple things that get you.

During initialization I init the watchdog as follows....

Chip_WWDT_Init(LPC_WWDT);

Chip_WWDT_SetTimeOut(LPC_WWDT, WDT_OSC / 1); // 1 second till reset

Chip_WWDT_SetOption(LPC_WWDT, WWDT_WDMOD_WDRESET);

Chip_WWDT_Start(LPC_WWDT);

Then as the program is running I do a ...

Chip_WWDT_Feed(LPC_WWDT); // every 10 mSec

The problem is that it always resets after 1 second. In the debugger, I see the WWDT_Feed() , loads the 0xAA, then 0x55 in plenty of time but the TV register doesn't get set back to the TC setting.

The LPC4078 seems only to have the dedicated watchdog oscillator and it is taking about 1 second to reset.

Any thoughts?

Re: LPC4078 Watchdog timer always resets

billbrown — Mon, 08 Aug 2016 18:45:54 GMT

Fixed it.

I needed to add the following to the init routine.

Chip_WWDT_Init(LPC_WWDT);

Chip_WWDT_SetTimeOut(LPC_WWDT, WDT_OSC / 1); // 1 second till reset

Chip_WWDT_SetWindow(LPC_WWDT, 0); //necessary

Chip_WWDT_SetOption(LPC_WWDT, WWDT_WDMOD_WDRESET);

Chip_WWDT_Start(LPC_WWDT);

You must insure that the window feature is not preventing the feeding of the dog to occur.

topic LPC4078 Watchdog timer always resets in LPC Microcontrollers

LPC4078 Watchdog timer always resets

Re: LPC4078 Watchdog timer always resets