© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 01 — 15 August 2005
290
Philips Semiconductors
UM10139
Volume 1
Chapter 20: WDT
Fig 64. Watchdog block diagram
PLCK
WDTV
register
Under
flow
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.
WDRESET
2
WDINT
WDTOF
WDEN
2
WDMOD
Register
Reset
Interrupt
SHADOW BIT
Enable
count
1
32 BIT DOWN
COUNTER
CURRENT WD
TIMER COUNT
/ 4
WDFEED
WDTC
Feed OK
Feed error
Feed
sequence