static void platform_systimer_init()
{
PIT_SetPIV( SYSTIMER_LIMIT );
AIC_ConfigureIT( AT91C_ID_SYS, 0, ISR_Pit );
PIT_EnableIT();
AIC_EnableIT( AT91C_ID_SYS );
PIT_Enable();
}
void PitInit(unsigned int msperiod)
{
PIT_DisableIT();
// Initialize the PIT to the desired frequency
PIT_Init(0, 0);
// PIT timer runs at MCK/16
// calculates the PIT Value accurate to a Millisecond interrupt
// msperiod can not be larget than 349 because PIV is at a 20bit limit
if(msperiod > 349) msperiod = 349;
PIT_SetPIV((MCK/(16*1000))*msperiod);
// Configure interrupt on PIT
AIC_DisableIT(AT91C_ID_SYS);
AIC_ConfigureIT(AT91C_ID_SYS, AT91C_AIC_PRIOR_LOWEST, ISR_Pit);
AIC_EnableIT(AT91C_ID_SYS);
PIT_EnableIT();
// Enable the pit
PIT_Enable();
}
