main.c

开发环境：ADS。测试usart0

// Include Standard files
#include "AT91SAM7X-EK.h"
#include "AT91SAM7X256.h"
#include "lib_AT91SAM7X256.h"


#define USART0_INTERRUPT_LEVEL		6
#define USART1_INTERRUPT_LEVEL		7
#define TIMER0_INTERRUPT_LEVEL		1
#define TIMER1_INTERRUPT_LEVEL		7
#define AT91_BAUD_RATE				115200
#define	WAIT_TIME					AT91B_MCK

/*-----------------*/
/* Clock Selection */
/*-----------------*/
#define TC_CLKS                  0x7
#define TC_CLKS_MCK2             0x0
#define TC_CLKS_MCK8             0x1
#define TC_CLKS_MCK32            0x2
#define TC_CLKS_MCK128           0x3
#define TC_CLKS_MCK1024          0x4

int count_timer0_interrupt;
static const char szembed_header[]=
{
"\n\r================================================"
"\n\r==         Test Timer Program                 =="
"\n\r================================================\n\r"
};

//*--------------------------------------------------------------------------------------
//* Function Name       : Usart_Send_One_Character
//* Object              : Test
//* Input Parameters    : one char to send
//* Output Parameters   : none
//*--------------------------------------------------------------------------------------
void Usart_Send_One_Char(int character)
{
	unsigned int status;
	AT91PS_USART COM0 = AT91C_BASE_US0;
	status = COM0 -> US_CSR;
	while ( (status & AT91C_US_TXRDY) == 0 )
	{
		status = COM0 -> US_CSR;
	}
	AT91F_US_PutChar(COM0 , character);
}

//*----------------------------------------------------------------------------
//* Function Name       : Usart_c_irq_handler
//* Object              : C handler interrupt function 
//* Input Parameters    : none
//* Output Parameters   : none
//*----------------------------------------------------------------------------
void Usart_c_irq_handler(void)
{
	AT91PS_USART COM0 = AT91C_BASE_US0;
	unsigned int status;
	//* get Usart status register
	status = COM0->US_CSR;
	if ( status & AT91C_US_RXRDY)
	{
	//* Get byte and send
		AT91F_US_PutChar(COM0,AT91F_US_GetChar(COM0));
	}
	//* Check error
	if ( status & AT91C_US_FRAME)
	{
		AT91F_US_PutChar (COM0, 'F');
	}
	//* Reset the satus bit
	COM0 ->US_CR = AT91C_US_RSTSTA;
}

//*----------------------------------------------------------------------------
//* Function Name       : Usart_init
//* Object              : USART initialization
//* Input Parameters    : none
//* Output Parameters   : TRUE
//*----------------------------------------------------------------------------
void Usart_init ( void )
{
	AT91PS_USART COM0 = AT91C_BASE_US0;
   	// First, enable the clock of the USART
	AT91F_PMC_EnablePeriphClock ( AT91C_BASE_PMC, 1 << AT91C_ID_US0 ) ;
	//* Configure PIO controllers to periph mode
	AT91F_PIO_CfgPeriph( AT91C_BASE_PIOA,
 		((unsigned int) AT91C_PA0_RXD0    ) |
 		((unsigned int) AT91C_PA1_TXD0    ) |
 		((unsigned int) AT91C_PA3_RTS0    ) |
 		((unsigned int) AT91C_PA4_CTS0    ), // Peripheral A
 		0); // Peripheral B
	// Usart Configure
	AT91F_US_Configure (COM0, AT91B_MCK, AT91C_US_ASYNC_MODE, AT91_BAUD_RATE, 0);
	// Enable usart
	COM0->US_CR = AT91C_US_RXEN | AT91C_US_TXEN;
	//* Enable USART IT error and RXRDY
    AT91F_US_EnableIt(COM0, AT91C_US_FRAME | AT91C_US_RXRDY);
   	//* open Usart 0 interrupt
	AT91F_AIC_ConfigureIt ( AT91C_BASE_AIC, AT91C_ID_US0, USART0_INTERRUPT_LEVEL,AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, Usart_c_irq_handler);
	AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_US0);
 	AT91F_US_SendFrame(COM0,(char *)szembed_header,sizeof(szembed_header),0,0);
}

void AT91F_TC_Open ( AT91PS_TC TC_pt, unsigned int Mode, unsigned int TimerId)
{
    unsigned int dummy;
    //* First, enable the clock of the TIMER
    AT91F_PMC_EnablePeriphClock ( AT91C_BASE_PMC, 1<< TimerId ) ;
    //* Disable the clock and the interrupts
	TC_pt->TC_CCR = AT91C_TC_CLKDIS ;
	TC_pt->TC_IDR = 0xFFFFFFFF ;
    //* Clear status bit
	dummy = TC_pt->TC_SR;
    //* Suppress warning variable "dummy" was set but never used
	dummy = dummy;
    //* Set the Mode of the Timer Counter
	TC_pt->TC_CMR = Mode ;
	//* Enable the clock
	TC_pt->TC_CCR = AT91C_TC_CLKEN ;
}

//*----------------------------------------------------------------------------
//* Function Name       : timer0_c_irq_handler
//* Object              : C handler interrupt function calAT91B_LED by the interrupts
//*                       assembling routine
//* Output Parameters   : increment count_timer0_interrupt
//*----------------------------------------------------------------------------
void timer0_c_irq_handler(void)
{
	AT91PS_TC TC_pt = AT91C_BASE_TC0;
    unsigned int dummy;
    //* AcknowAT91B_LEDge interrupt status
    dummy = TC_pt->TC_SR;
    //* Suppress warning variable "dummy" was set but never used
    dummy = dummy;
    count_timer0_interrupt++;
    //* Read the output state
   	Usart_Send_One_Char('\n');
   	Usart_Send_One_Char('\r');   	
}

//*----------------------------------------------------------------------------
//* Function Name       : timer_init
//* Object              : Init timer counter
//* Input Parameters    : none
//* Output Parameters   : TRUE
//*----------------------------------------------------------------------------

void timer_init ( void )
{
    //init the timer interrupt counter
    count_timer0_interrupt=0;
    //* Open timer0
	AT91F_TC_Open(AT91C_BASE_TC0,TC_CLKS_MCK1024,AT91C_ID_TC0);
    //* Open Timer 0 interrupt
	AT91F_AIC_ConfigureIt ( AT91C_BASE_AIC, AT91C_ID_TC0, TIMER0_INTERRUPT_LEVEL,AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, timer0_c_irq_handler);
	AT91C_BASE_TC0->TC_IER = AT91C_TC_CPCS;  //  IRQ enable CPC
	AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_TC0);
    //* Start timer0
    AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG ;
}

//*----------------------------------------------------------------------------
//* Function Name       : delay
//* Object              : Wait
//* Input Parameters    : none
//* Output Parameters   : none
//* Functions calAT91B_LED    : none
//*----------------------------------------------------------------------------
void delay ( void )
{
//* Set in Volatile for Optimisation
    volatile unsigned int    i ;
//* loop delay
    for ( i = 0 ;(i < WAIT_TIME/50 );i++ ) ;
}

//*--------------------------------------------------------------------------------------
//* Function Name       : Main
//* Object              : Software entry point
//* Input Parameters    : none.
//* Output Parameters   : none.
//*--------------------------------------------------------------------------------------
int main()
{
	int test_char;
	Usart_init();
	timer_init();
	delay();
	for(test_char='A';;(test_char=='Z')?(test_char='A'):(test_char++))
	{
		Usart_Send_One_Char(test_char);
		delay();
    }
}