4.S5PV210看门狗定时器相关寄存器描述

看门狗

1、Watchdog Timer Control Register (WTCON, R/W, Address = 0xE270_0000)

The WTCON register allows you to enable/ disable the watchdog timer, select the clock signal from four different sources, enable/ disable interrupts, and enable/ disable the watchdog timer output.The Watchdog timer is used to restart the S5PV210 to recover from mal-function; if controller restart is not
desired, the Watchdog timer should be disabled.If you want to use the normal timer provided by the Watchdog timer, enable the interrupt and disable the Watchdog timer.
看门狗定时器控制寄存器
WTCON寄存器允许你使能/禁止看门狗定时器，可以从四个不同的时钟源选择一个作为时钟信号，使能/禁止中断，使能/禁止看门狗定时器复位输出。看门狗定时器被用来在S5PV210发生故障时复位系统。如果不希望控制器复位可以禁止看门狗定时器，如果你想通过看门狗定时器使用正常的定时功能，你可以使能中断并禁止看门狗功能。


2、Watchdog Timer Data Register (WTDAT, R/W, Address = 0xE270_0004)
The WTDAT register specifies the time-out duration. The content of WTDAT cannot be automatically loaded into the timer counter at initial watchdog timer operation. However, using 0x8000 (initial value) drives the first time-out.In this case, the value of WTDAT is automatically reloaded into WTCNT.
WTDAT寄存器指定超时时间。在看门狗定时器刚启动时WTDAT中的值不能被自动装载进定时器计数器中。然而，WTCNT第一次的初始值为0x8000。然后接着WTDAT中的值会自动重装载进WTCNT中。


3、Watchdog Timer Count Register (WTCNT, R/W, Address = 0xE270_0008)
The WTCNT register contains the current count values for the watchdog timer during normal operation. Note that the content of the WTDAT register cannot be automatically loaded into the timer count register if the watchdog timer is enabled initially, therefore the WTCNT register must be set to an initial value before enabling it.
WTCNT寄存器包含看门狗定时器正常运行时的当前计数值。在看门狗定时器刚启动时WTDAT中的值不能被自动装载进定时器计数器中，因此在初始化看门狗定时器的时候最开始给它一个初值。


4、Watchdog Timer Interrupt Clear Register (WTCLRINT, W, Address = 0xE270_000C)
The WTCLRINT register is used to clear the interrupt. Interrupt service routine is responsible to clear the relevant interrupt after the interrupt service is complete. Writing any values on this register clears the interrupt. Reading this register is not allowed.

WTCLRINT寄存器被用来清除中断使用。在中断完成后由isr来清除相应的中断。在这个寄存器中随便写入一个值就可以清除中断。不能读这个寄存器的值。