| /* | |
| * File: wdog.c | |
| * Purpose: Provide common watchdog module routines | |
| * | |
| * Notes: Need to add more functionality. Right now it | |
| * is just a disable routine since we know almost | |
| * all projects will need that. | |
| * | |
| */ | |
| #include "common.h" | |
| #include "wdog.h" | |
| /********************************************************************/ | |
| /* | |
| * Watchdog timer disable routine | |
| * | |
| * Parameters: | |
| * none | |
| */ | |
| void wdog_disable(void) | |
| { | |
| /* First unlock the watchdog so that we can write to registers */ | |
| wdog_unlock(); | |
| /* Clear the WDOGEN bit to disable the watchdog */ | |
| WDOG_STCTRLH &= ~WDOG_STCTRLH_WDOGEN_MASK; | |
| } | |
| /********************************************************************/ | |
| /* | |
| * Watchdog timer unlock routine. Writing 0xC520 followed by 0xD928 | |
| * will unlock the write once registers in the WDOG so they are writable | |
| * within the WCT period. | |
| * | |
| * Parameters: | |
| * none | |
| */ | |
| void wdog_unlock(void) | |
| { | |
| /* NOTE: DO NOT SINGLE STEP THROUGH THIS FUNCTION!!! */ | |
| /* There are timing requirements for the execution of the unlock. If | |
| * you single step through the code you will cause the CPU to reset. | |
| */ | |
| /* This sequence must execute within 20 clock cycles, so disable | |
| * interrupts will keep the code atomic and ensure the timing. | |
| */ | |
| DisableInterrupts; | |
| /* Write 0xC520 to the unlock register */ | |
| WDOG_UNLOCK = 0xC520; | |
| /* Followed by 0xD928 to complete the unlock */ | |
| WDOG_UNLOCK = 0xD928; | |
| /* Re-enable interrupts now that we are done */ | |
| EnableInterrupts; | |
| } | |
| /********************************************************************/ |