LED 流水灯实验代码 S3C2440A TQ2440 keil uvision4

#include "S3C2440.h" /* S3C2440 definitions */ #define LED1_MASK 0x0020 #define LED2_MASK 0x0040 #define LED3_MASK 0x0080 #define LED4_MASK 0x0100 void Delay(int n); int main() { unsigned long nLED; nLED = 0; while(1) { nLED = 0; nLED ^=(LED2_MASK | LED3_MASK | LED4_MASK); // LED1 light GPBDAT = nLED; Delay(300); nLED = 0; nLED ^=(LED1_MASK | LED3_MASK | LED4_MASK); // LED2 light GPBDAT = nLED; Delay(300); nLED = 0; nLED ^=(LED1_MASK | LED2_MASK | LED4_MASK); // LED3 light GPBDAT = nLED; Delay(300); nLED = 0; nLED ^=(LED1_MASK | LED2_MASK | LED3_MASK); // LED3 light GPBDAT = nLED; Delay(300); } } void Delay(int n) { int i,j; for(i=0;i<n;i++) { for(j=0;j<n;j++) { } } }