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Philips Semiconductors
Preliminary User Manual
LPC2119/2129/2292/2294
ARM-based Microcontroller
BLOCK DIAGRAM
The block diagram of the Watchdog is shown below in the Figure 45.
Figure 45: Watchdog Block Diagram
WDEN
2
SHADOW BIT
WDINT
FEED
SEQUENCE
WDFEED
32-BIT DOWN
COUNTER
WDTC
WDTOF
pclk
RESET
WDMOD
REGISTER
/ 4
INTERRUPT
FEED OK
FEED ERROR
WDRESET
2
CURRENT WD
TIMER COUNT
WDTV
REGISTER
1. Counter is enabled only when the WDEN bit is set
and a valid feed sequence is done.
2. WDEN and WDRESET are sticky bits. Once set
they can’t be cleared until the Watchdog underflows
or an external reset occurs.
ENABLE
COUNT
1
UNDER
FLOW