an example C code using PRUSS-C libraries

blinkledv1

#include <gpio_v2.h>
#include <soc_AM335x.h>
//#include "blink.h"
#define PRU0_ARM_INTERRUPT 	19
#define AM33XX
#define GPIO1 			(*(volatile unsigned long *)(0x4804c000))		// The address of the GPIO1 
#define GPIO_INSTANCE_ADDRESS           (SOC_GPIO_1_REGS)
#define SYSCFG (*(&C4+0x01))
int C4 __attribute__((cregister("MEM",near),peripheral));	//only compatible with v1.1.0B1 +
								//add following lines to MEMORY{} in lnk.cmd
								//PAGE 2:
								//	MEM : o = 0x00026000 l = 0x00002000 CREGISTER=4
								
volatile register unsigned int __R31;
static void blink1(void);
static void blink2(void);

void main(void)
{
	/*Intialise OCP Master port for accessing external memories*/
	SYSCFG&=0xFFFFFFEF;
	/*Start Main Code*/
	blink1();
	
	blink2();
	/*Exiting procedure*/
	__R31 = 35;			// Send notification to Host for program completion
	__halt();			//only compatible with v2.0.0B1 + for lower verions of Compiler use
					//asm(" HALT");
}

/*Blink user led 2,3 twice and stay ON*/
static void blink1(void)
{
	unsigned int i;
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 23, GPIO_PIN_LOW);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 24, GPIO_PIN_LOW);

        for(i=0;i<0x00a00000;i++);

        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 23, GPIO_PIN_HIGH);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 24, GPIO_PIN_HIGH);
 
        for(i=0;i<0x00a00000;i++);

        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 23, GPIO_PIN_LOW);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 24, GPIO_PIN_LOW);

        for(i=0;i<0x00a00000;i++);

        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 23, GPIO_PIN_HIGH);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 24, GPIO_PIN_HIGH); 
        for(i=0;i<0x00a00000;i++);

}

/*Blink userled 0,1 twice and stay on */
static void blink2(void)
{
        unsigned int i;
	GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 21, GPIO_PIN_LOW);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 22, GPIO_PIN_LOW);

        for(i=0;i<0x00a00000;i++);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 21, GPIO_PIN_HIGH);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 22, GPIO_PIN_HIGH);
 
        for(i=0;i<0x00a00000;i++);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 21, GPIO_PIN_LOW);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 22, GPIO_PIN_LOW);

        for(i=0;i<0x00a00000;i++);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 21, GPIO_PIN_HIGH);
        GPIOPinWrite(GPIO_INSTANCE_ADDRESS, 22, GPIO_PIN_HIGH);

        for(i=0;i<0x00a00000;i++);
}