#include  "LPC21XX.h"

int main(void)
{
	//设置P0_9为输出模式
	PINSEL0=0;
	IO0DIR=0x00000200;
	IO0SET=(0x00000001<<9);
	while(1)
	{
		if((IO0PIN&0x00008000)==0x00008000)
			IO0SET=0x0000200;
		else
			IO0CLR=0x00000200;	
	}
}