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Watchdog Timer
LH75400/01/10/11 (Preliminary) User’s Guide
16-2
6/17/03
16.2 WDT Theory of Operation
All Control and Status Registers for the Watchdog Timer can be accessed through the
APB. The Watchdog Timer consists of a 32-bit down-counter that causes a selectable
time-out interval to detect malfunctions. The timer needs to be periodically reset by soft-
ware. Failure to do so results in a time-out that causes an interrupt to be taken or a System
Reset to be issued by the RCPC. There are 16 selectable time intervals for a time-out of
2
16
through 2
31
system clock cycles.
See Chapter 9 for a complete description about reset generation.
16.3 WDT Programmer’s Model
The base address for the WDT is:
WDT Base Address: 0xFFFE3000
16.3.0.1 WDT Register Summary
Table 16-1. WDT Register Summary
NAME ADDRESS OFFSET TYPE RESET VALUE
DESCRIPTION
CTRL
0x00
R W
0x00
Watchdog Control Register
CNTR
0x04
W
—
Watchdog Counter Reset
TSTR
0x08
R W
0x40
Watchdog Register
CNT0
0x0C
R
0x00
WDT Counter Section 0
CNT1
0x10
R
0x00
WDT Counter Section 1
CNT2
0x14
R
0x01
WDT Counter Section 2
CNT3
0x18
R
0x00
WDT Counter Section 3