我想串口程序应该是ARM程序中最简略的了吧。尽管如此，做个记载吧 。
详细设置如下：
#define ULCON0 (*((volatile unsigned long *)0x7F005000))
#define UCON0 (*((volatile unsigned long *)0x7F005004))
#define UFCON0 (*((volatile unsigned long *)0x7F005008))
#define UMCON0 (*((volatile unsigned long *)0x7F00500C))
#define UTRSTAT0 (*((volatile unsigned long *)0x7F005010))
#define UFSTAT0 (*((volatile unsigned long *)0x7F005018))
#define UTXH0 (*((volatile unsigned char *)0x7F005020))
#define URXH0 (*((volatile unsigned char *)0x7F005024))
#define UBRDIV0 (*((volatile unsigned short *)0x7F005028))
#define UDIVSLOT0 (*((volatile unsigned short *)0x7F00502C))
#define GPACON (*((volatile unsigned long *)0x7F008000))
void init_uart(void)
{
GPACON &= ~0xff;
GPACON |= 0x22;
/* ULCON0 */
ULCON0 = 0x3; /* 数据位:8, 无较验, 中止位: 1, 8n1 */
UCON0 = 0x5; /* 使能UART发送、接纳 */
UFCON0 = 0x01; /* FIFO ENABLE */
UMCON0 = 0;
/* 波特率 */
/* DIV_VAL = (PCLK / (bps x 16 ) ) – 1
*PCLK = 66.5MHz
* bps = 115200
* DIV_VAL = (66500000 / (115200 x 16 ) ) – 1
* = 35.08
*/
UBRDIV0 = 35;
/* x/16 = 0.08
* x = 1
*/
UDIVSLOT0 = 0x1;
}
char getchar(void)
{
while ((UFSTAT0& (1<<6)) == 0 && (UFSTAT0& 0x3f) == 0);
return URXH0;
}
void putchar(char c)
{
while ((UFSTAT0 & (1<<14)) );
UTXH0 = c;
}
在主函数中调用上面的串口初始化函数，接纳字符串函数和发送字符穿函数，如下，经过键盘在串口助手中向串口发送字符，则会有“输入字符+1”显现在终端上。
{
char c;
init_uart();
while (1)
{
c = getchar();
putchar(c+1);
}
return 0;
}
更改主函数与Uart.c函数，完成你想要的功用：
int main()
{
char c;
char* str = “—hello uart-arm—–\r\n”;
char* addition =”—addition operation—-\r\n”;
char* of1 = “a. hello\r\n”;
char* of2 = “b. what is your name\r\n”;
char* of3 = “c. belief\r\n”;
char a,b ; char sum;
char choice;
init_uart();
//print str
c = getchar();
putchar(c+1);
putstr(str);
//addition operation
putstr(addition);
putstr(of1);
putstr(of2);
putstr(of3);
while(1){
choice = getchar();
if(choice ==a)
putstr(“hello\r\n”);
else
if (choice ==b)
putstr(“what is your name\r\n”);
else
if (choice ==c)
putstr(“belief\r\n”);
else
putstr(“no option\r\n”);
}}
上面函数相当于一个简略的菜单挑选。 输出如下，以下成果是顺次从键盘输入a,b,c,d,e之后的成果
