硬件部分：mini2440的GPB5~8引脚分别连接着LED1~4。

#define GPBCON (*(volatile unsigned long *)0x56000010) /* GPB端口控制寄存器地址*/

#define GPBDAT (*(volatile unsigned long *)0x56000014) /* GPB端口数据寄存器地址*/

#define LOCKTIME        (*(volatile unsigned long *)0x4C000000)

#define MPLLCON         (*(volatile unsigned long *)0x4C000004) /* MPLLCON寄存器地址 */

#define UPLLCON         (*(volatile unsigned long *)0x4C000008)

#define GPB5_out (1<<(5*2)) /* GPB5是由GPBCON的bit[11:10]两位来控制 */

#define GPB6_out (1<<(6*2)) /* 00-input 01-output */

#define GPB7_out (1<<(7*2)) /* 明确由输出高电平还是由低电平来点亮 */

#define GPB8_out (1<<(8*2)) /* 故要将GPB5678四个IO口设置为输出      */

/* FCLK = 271.5M */

#define M_MDIV 0xad

#define M_PDIV 2

#define M_SDIV 2

#define U_MDIV 0x38

#define U_PDIV 2

#define U_SDIV 2

/*** 延时函数*/

void wait(unsigned long time)

{

     int i;

     for (i = 0; i < time; i++);

}

int main(void) /* 主函数 */

{

unsigned long j,i = 0;

     GPBCON = GPB5_out|GPB6_out|GPB7_out|GPB8_out; /* 将LED对应的GPB5678四个引脚设为输出*/

     LOCKTIME = 0xFFFFFF;

     UPLLCON = ((U_MDIV << 12) + (U_PDIV << 4) + U_SDIV);

     delay(0xffff);

     delay(0xffff);

     MPLLCON = ((M_MDIV << 12) + (M_PDIV << 4) + M_SDIV);

     delay(0xffff);

delay(0xffff);

while(1)

{        

     for (j = 0; j < 10; j++){

    delay(0xffff);

     }

     GPBDAT = (~(i<<5));

     if(++i == 16)

    i = 0;      

     }

     return 0;

}

/**说明**/

S3c2440在时钟设置时，需要先设置UPLLCON寄存器，后设置MPLLCON寄存器，而且之间还需要有一定的延时。

5：编译，下载调试。