Dolphin Technology provides Watchdog Timer (WDT) IP which is used to prevent system lockup if software becomes trapped in a deadlock by generating a system reset, an interrupt, or an external signal. The IP is programmable by a standard APB Slave peripheral which is used periodically by Software to control the watchdog by writing to it to reset its timeout counters.
AMBA, Advanced Peripheral Bus (APB) Specification Version 2.0
AMBA, Advanced High-performance Bus (AHB) Specification Version 2.0
AMBA, Advanced eXtensibale Bus (AXI) Specification Version 4.0
AMBA, Advanced eXtensibale Lite Bus (AXI-Lite) Specification Version 4.0
DTI WDT Controller supports:
32 bit APB bus width.
WDT can perform two types of operations when timeout occurs:
Generate a system reset.
First generate an interrupt and even if it is cleared (or not cleared) by the service routine by the time a second timeout occurs then generate a system reset.
Pause mode for debugging
Programmable reset pulse length
Prevention of accidental restart of the watchdog counter
Prevention of accidental disabling of the watchdog counter
32 bits WDT counter width
Counter counts down from a preset value to 0 to indicate the occurrence of a timeout
Optional external clock signal to control the rate at which the counter counts
Optional support for asynchronous external timer clock. With this feature enabled, the timer interrupt and system reset can be generated, even when the APB bus clock is switched off
Software interface consistent with AMBA Advanced Peripheral Bus (APB), Advanced High-performance bus (AHB) or Advanced eXtensible Interface (AXI)