/*
* The application must provide a function that configures a peripheral to
* create the FreeRTOS tick interrupt, then define configSETUP_TICK_INTERRUPT()
* in FreeRTOSConfig.h to call the function. This file contains a function
* that is suitable for use on the Atmel SAMA5.
*/
void vConfigureTickInterrupt( void )
{
/* NOTE: The PIT interrupt is cleared by the configCLEAR_TICK_INTERRUPT()
macro in FreeRTOSConfig.h. */
/* Enable the PIT clock. */
PMC->PMC_PCER0 = 1 << ID_PIT;
/* Initialize the PIT to the desired frequency - specified in uS. */
PIT_Init( 1000000UL / configTICK_RATE_HZ, BOARD_MCK / 1000000 );
/* Configure interrupt on PIT. Note this is on the system interrupt, which
is shared with other system peripherals, so System_Handler() must be
installed in place of FreeRTOS_Tick_Handler() if other system handlers are
required. The tick must be given the lowest priority (0 in the SAMA5 AIC) */
IRQ_ConfigureIT( ID_PIT, AIC_SMR_SRCTYPE_EXT_POSITIVE_EDGE, FreeRTOS_Tick_Handler );
/* See commend directly above IRQ_ConfigureIT( ID_PIT, 0, System_Handler ); */
IRQ_EnableIT( ID_PIT );
PIT_EnableIT();
/* Enable the pit. */
PIT_Enable();
/* Prevent compiler warnings in the case where System_Handler() is not used
as the handler. See the comments above the System_Handler() function
prototype at the top of this file. */
( void ) System_Handler;
}
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();
}
/**
* \brief Configures the PIT & reset tickCount.
* Systick interrupt handler will generates 1ms interrupt and increase a
* tickCount.
* \note IRQ handler must be configured before invoking this function.
* \note PIT is enabled automatically in this function.
* \param new_mck Current master clock.
*/
extern uint32_t TimeTick_Configure( uint32_t new_mck )
{
_dwTickCount = 0 ;
PIT_Init( 1000, new_mck / 1000000 );
PIT_EnableIT();
PIT_Enable();
return 0;
}
static void prvSetupTimerInterrupt( void )
{
const uint32_t ulPeriodIn_uS = ( 1.0 / ( double ) configTICK_RATE_HZ ) * port1SECOND_IN_uS;
/* Setup the PIT for the required frequency. */
PIT_Init( ulPeriodIn_uS, BOARD_MCK / port1MHz_IN_Hz );
/* Setup the PIT interrupt. */
AIC_DisableIT( AT91C_ID_SYS );
AIC_ConfigureIT( AT91C_ID_SYS, AT91C_AIC_PRIOR_LOWEST, vPortTickISR );
AIC_EnableIT( AT91C_ID_SYS );
PIT_EnableIT();
}
unsigned long int SysTick_Config(unsigned long int ticks)
{
unsigned long int rate = SystemCoreClock/ticks;
/* Configure timer to interrupt specified times per second */
PIT_Init(1000000/rate, SystemCoreClock/1000000);
PIT_EnableIT();
PIT_Enable();
/* Configure timer interrupt */
AIC_ConfigureIT(AT91C_ID_SYS, AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, TimerISR);
AIC_EnableIT(AT91C_ID_SYS);
return 0;
}
//------------------------------------------------------------------------------
/// Configures the PIT to generate 1ms ticks.
//------------------------------------------------------------------------------
static void ConfigurePit(void)
{
// Initialize and enable the PIT
PIT_Init(PIT_PERIOD, BOARD_MCK / 1000000);
// Disable the interrupt on the interrupt controller
IRQ_DisableIT(AT91C_ID_SYS);
// Configure the AIC for PIT interrupts
IRQ_ConfigureIT(AT91C_ID_SYS, 0, ISR_Pit);
// Enable the interrupt on the interrupt controller
IRQ_EnableIT(AT91C_ID_SYS);
// Enable the interrupt on the pit
PIT_EnableIT();
// Enable the pit
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();
}
/*
* The application must provide a function that configures a peripheral to
* create the FreeRTOS tick interrupt, then define configSETUP_TICK_INTERRUPT()
* in FreeRTOSConfig.h to call the function. This file contains a function
* that is suitable for use on the Atmel SAMA5.
*/
void vConfigureTickInterrupt( void )
{
/* NOTE: The PIT interrupt is cleared by the configCLEAR_TICK_INTERRUPT()
macro in FreeRTOSConfig.h. */
/* Enable the PIT clock. */
PMC->PMC_PCER0 = 1 << ID_PIT;
/* Initialize the PIT to the desired frequency - specified in uS. */
PIT_Init( 1000000UL / configTICK_RATE_HZ, ( BOARD_MCK / 2 ) / 1000000 );
/* Enable IRQ / select PIT interrupt. */
PMC->PMC_PCER1 = ( 1 << ( ID_IRQ - 32 ) );
AIC->AIC_SSR = ID_PIT;
/* Ensure interrupt is disabled before setting the mode and installing the
handler. The priority of the tick interrupt should always be set to the
lowest possible. */
AIC->AIC_IDCR = AIC_IDCR_INTD;
AIC->AIC_SMR = AIC_SMR_SRCTYPE_EXT_POSITIVE_EDGE;
AIC->AIC_SVR = ( uint32_t ) FreeRTOS_Tick_Handler;
/* Start with the interrupt clear. */
AIC->AIC_ICCR = AIC_ICCR_INTCLR;
/* Enable the interrupt in the AIC and peripheral. */
AIC_EnableIT( ID_PIT );
PIT_EnableIT();
/* Enable the peripheral. */
PIT_Enable();
/* Prevent compiler warnings in the case where System_Handler() is not used
as the handler. See the comments above the System_Handler() function
prototype at the top of this file. */
( void ) System_Handler;
}
