按键的轮询

　　早上依旧七点不到就醒了，不知道是不是一年多来差不多都习惯了，想想大一大二都是九点后才醒的，现在真的不知道哪里来的精神。作为一个“插班生”，总要比别个努力一点，努力不丢人，，今天主要任务是裸机，s5pv210 的降频，

#define GPJ2CON *((volatile unsigned int *)0xE0200280)
#define GPJ2PUD *((volatile unsigned int *)0xE0200288)
#define GPJ2DAT *((volatile unsigned int *)0xE0200284)

#define APLL_CON0 *((volatile unsigned int *)0xE0100100)

extern void delay(void);

void chang_clock(void)
{
APLL_CON0 = APLL_CON0 |0x807d0302;   //只有一行，嵌入式就是这样，短短的一行代码，后面就是不知道多少资料的翻阅
}

void main(void)
{

GPJ2CON = 0x1111;
GPJ2PUD = 0xaa;
GPJ2DAT = 0xf;

chang_clock();

while(1)
{
GPJ2DAT = 0x0;
delay();
GPJ2DAT = 0xf;
delay();
}
}

　　还做了按键轮询的裸机驱动，如下

#define GPJ2CON *((volatile unsigned int *)0xE0200280)
#define GPJ2PUD *((volatile unsigned int *)0xE0200288)
#define GPJ2DAT *((volatile unsigned int *)0xE0200284)

#define GPH2CON *((volatile unsigned int *)0xE0200C40)
#define GPH2PUD *((volatile unsigned int *)0xE0200C48)
#define GPH2DAT *((volatile unsigned int *)0xE0200C44)

/*
#define GPH3CON *((volatile unsigned int *)0xE0200C60)
#define GPH3PUD *((volatile unsigned int *)0xE0200C68)
#define GPH3DAT *((volatile unsigned int *)0xE0200C64)

GPH3CON = 0x00;
GPH3PUD = 0xaa;
//GPH3DAT = 0xff; //输入的时候是不能赋初值的

*/
extern void delay(void);

void main(void)
{
GPJ2CON = 0x1111;
GPJ2PUD = 0xaa;
GPJ2DAT = 0xf;

GPH2CON = 0x00;
GPH2PUD = 0xaa;//这里只是配置了四位，所以下面判断时用0e,od,ob,o7
//GPH2DAT = 0xff; //输入的时候是不能赋初值的

while(1)
{
delay();

if(GPH2DAT == 0x0e)
{
GPJ2DAT = GPJ2DAT ^1; //班上小美女想的，神来之笔，学习了
}

if(GPH2DAT == 0x0d)
{
GPJ2DAT = GPJ2DAT ^2; //每次进来只要和相应位异或就可以取反
}

if(GPH2DAT == 0x0b)
{
GPJ2DAT = GPJ2DAT ^4;
}

if(GPH2DAT == 0x07)
{
GPJ2DAT =GPJ2DAT ^8;
}
}
}

　　智力不够努力凑，人丑就要多学习。