LPC5526 Maximum Watchdog timeout value

[jtauch1]

From LPC55S6x/LPC55S2x/LPC552x User manual ch30

I just want to confirm that the following is the max watchdog time-out value. If this is the case is there 

any way to reach a time-out value of 10 minutes.

The user manual says:

The watchdog consists of a fixed (divide by 4) pre-scaler and a 24-bit counter which
decrements when clocked. This provides a  selectable time period from 1,024 watchdog clocks (TWDCLK × 256 × 4) to over 67 million watchdog clocks (TWDCLK × 2^24 × 4) in increments of four watchdog clocks.

Given that WDTCLK is 1MHZ and has a fixed divide by 4 = 250KHz, then the max timeout value is approx 268 sec or 4.47 min. 

Is the above correct? If so is there any way to change the Watchdog clock to a slower clock? ideally, we would like to have a 10 minute timeout value.

Thanks,

John

[Xu_Zhang]

hi,jtauch1

 The way you calculate the watchdog's maximum timeout value is fine, and if you want to change the watchdog clock to a slower clock, you can focus on the WDTCLKDIV register.

BR

Xu Zhang