void NDS32ATTR_ISR("not_nested;id=0") HW0_ISR(void)
{
   puts("* Enter HW0 ISR with GPIO *\n");
   outw(GPIO_BASE + GPIO_IC_OFFSET, 0xFFFFFFFF);

   /* This service will take 6 secs */
   unsigned int period;
   period = (6 * (MB_PCLK / TICK_HZ)) >> SIMU_FACTOR;
   outw(TM2_LOAD, period);
   outw(TM2_CNTR, 0);
   outw(TM_CR, (inw(TM_CR) | TM_CR_TM2ENA | TM_CR_TM2UP));
   while (1) {
      unsigned int tm2_cntr = inw(TM2_CNTR);
      if (tm2_cntr > period)
         break;
   }
   puts("* End of HW0 ISR it takes 6 secs *\n");
}