224
Philips Semiconductors
Preliminary User Manual
LPC2119/2129/2292/2294
ARM-based Microcontroller
Watchdog Mode Register (WDMOD - 0xE0000000)
The WDMOD register controls the operation of the Watchdog as per the combination of WDEN and RESET bits.
WDEN
WDRESET
0
X
Debug/Operate without the Watchdog running
1
0
Debug with the Watchdog interrupt but no WDRESET
1
1
Operate with the Watchdog interrupt and WDRESET
Once the WDEN and/or WDRESET bits are set they can not be cleared by software. Both flags are cleared by an external reset
or a Watchdog timer underflow.
WDTOF
The Watchdog time-out flag is set when the Watchdog times out. This flag is cleared by software.
WDINT
The Watchdog interrupt flag is set when the Watchdog times out. This flag is cleared when any reset occurs.
Watchdog Timer Constant Register (WDTC - 0xE0000004)
The WDTC register determines the time-out value. Every time a feed sequence occurs the WDTC content is reloaded in to the
Watchdog timer. It’s a 32-bit register with 8 LSB set to 1 on reset. Writing values below 0xFF will cause 0xFF to be loaded to the
WDTC. Thus the minimum time-out interval is t
pclk
x 256 x 4.
Table 193: Watchdog Mode Register (WDMOD - 0xE0000000)
WDMOD
Function
Description
Reset Value
0
WDEN
Watchdog interrupt enable bit (Set only)
0
1
WDRESET
Watchdog reset enable bit (Set Only)
0
2
WDTOF
Watchdog time-out flag
0 (Only after
external reset)
3
WDINT
Watchdog interrupt flag (Read Only)
0
7:4
Reserved
Reserved, user software should not write ones to reserved bits. The value read
from a reserved bit is not defined.
NA
WDTC
Function
Description
Reset
Value
31:0
Count
Watchdog time-out interval
0xFF