#define _WDT_ON_MAX_PERIOD      { u8_t uc_ttt; \
 SAVE_IRQ_AND_DISABLE;   \
 __watchdog_reset();     \
 uc_ttt = WDTCR;         \
 uc_ttt |= ( (1 << WDCE) | (1 << WDE) ); \
 WDTCR = uc_ttt; \
 WDTCR = ( (1 << WDE) | (1 << WDP2) | (1 << WDP1) | (1<<WDP0) ); \
 __watchdog_reset();  \
 RESTORE_IRQ;   }