WRITE_ST
WRITE_ST(ST_IDR, -1); /* make sure interrupts are disabled */
WRITE_ST(ST_PIMR, AT91ST_DIVIDER);
WRITE_ST(ST_RTMR, 1);
WRITE_ST(ST_PIMR, AT91ST_DIVIDER);
WRITE_ST(ST_IER, ST_SR_PITS);