Philips LPC2119 User Manual page 225

Philips Semiconductors
ARM-based Microcontroller
Watchdog Feed Register (WDFEED - 0xE0000008)
Writing 0xAA followed by 0x55 to this register will reload the Watchdog timer to the WDTC value. This operation will also start
the Watchdog if it is enabled via the WDMOD register. Setting the WDEN
enable the Watchdog. A valid feed sequence must first be completed before the Watchdog is capable of generating an interrupt/
reset. Until then, the Watchdog will ignore feed errors. Once 0xAA is written to the WDFEED register the next operation in the
Watchdog register space should be a WRITE (0x55) to the WDFFED register otherwise the Watchdog is triggered. The interrupt/
reset will be generated during the second pclk following an incorrect access to a watchdog timer register during a feed sequence.
Table 194: Watchdog Feed Register (WDFEED - 0xE0000008)
WDFEED Function
7:0 Feed
Watchdog Timer Value Register (WDTV - 0xE000000C)
The WDTV register is used to read the current value of Watchdog timer.
Table 195: Watchdog Timer Value Register (WDTV - 0xE000000C)
WDTV Function
31:0 Count
Watchdog
Feed value should be 0xAA followed by 0x55
Current timer value
LPC2119/2129/2292/2294
bit in the WDMOD register is not sufficient to
Description
Description
225
Preliminary User Manual
Reset
Value
undefined
Reset
Value
0xFF
January 08, 2004