问个非常弱智 的问题，请各位前辈指教！！！跪谢！！

s3c2410开发板上一个led点亮的问题，下载后直接运行，，程序运行时显示：SWI exception.....

.h头文件：

#ifdef __cplusplus
extern "C" {
#endif

#define rGPFCON (*(volatile unsigned *)0x56000050) //Port F control
#define rGPFDAT (*(volatile unsigned *)0x56000054) //Port F data
#define rGPFUP (*(volatile unsigned *)0x56000058) //Pull-up control F
#define rWTCON (*(volatile unsigned *)0x53000000) //watchdog
#ifdef __cplusplus
}
#endif


.c源文件:

#include "address.h"
int main(void)
{
rWTCON = 0x0; 关定时狗
rGPFCON = 0x5500;引脚控制
rGPFUP = 0xffff;上啦电阻设置
while(1)
{
rGPFDAT = 0x90; //10010000 数据配置
}
return 0;
}