Microcontrollers User manual

UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 666 of 792
NXP Semiconductors
UM10237
Chapter 27: LPC24XX WatchDog Timer (WDT)
5. Block diagram
The block diagram of the Watchdog is shown below in the Figure 27–137. The
synchronization logic (PCLK - WDCLK) is not shown in the block diagram.
Fig 137. Watchdog block diagram
WDTC
32 BIT DOWN COUNTER
WDINT WDTOF WDRESET WDEN
SHADOW BIT
reset
interrupt
÷ 4
WDFEED
WDCLKSEL
RTC oscillator
pclk
internal RC oscillator
feed ok
feed error
wdclk
underflow
enable
count
WMOD register
feed sequence