ARM裸机篇-串口UART实验 - - Powered by Discuz!

void Uart_SendByte(int data)//这个函数是发送整型数据，参数为data
{
if(whichUart==0)//这个是选中串口0
{
if(data=='')//然后判断数据不为空
{
　　　　　　/*寄存器的原始宏定义，
　　　　　　#define rUTRSTAT0 (*(volatile unsigned *)0x50000010) //UART 0 Tx/Rx status*/
while(!(rUTRSTAT0 & 0x2));/*这个就是查询串口0的状态寄存器，第1位是发送缓冲器是否为空
第二位是Transmit buffer empty
0 = The buffer register is not empty
1 = Empty 这里检查为0的话就是还没发送完全，当置1的时候表示发完了，程序继续执行*/
Delay(10); //because the slow response of hyper_terminal
WrUTXH0('');
}
while(!(rUTRSTAT0 & 0x2)); //Wait until THR is empty.
Delay(10);
WrUTXH0(data);
}
else if(whichUart==1)
{
if(data=='')
{
while(!(rUTRSTAT1 & 0x2));
Delay(10); //because the slow response of hyper_terminal
rUTXH1 = '';
}
while(!(rUTRSTAT1 & 0x2)); //Wait until THR is empty.
Delay(10);
rUTXH1 = data;
}
else if(whichUart==2)
{
if(data=='')
{
while(!(rUTRSTAT2 & 0x2));
Delay(10); //because the slow response of hyper_terminal
rUTXH2 = '';
}
while(!(rUTRSTAT2 & 0x2)); //Wait until THR is empty.
Delay(10);
rUTXH2 = data;
}
}

复制代码

/***************************************************************************************
* Function Name : Main()
* Create Date : 2011/12/10
* Author/Corporation : 涛行天下
*
* Description : Find a proper thread in thread array
*
* Param : ThreadNo : someParam description
ThreadStaus : someParam description
*
*
* Global Variable : DISP_wuiSegmentAppID
* File Static Variable : naucThreadNo
* Function Static Variable : None
*
*----------------------------------------------------
* Revision History
* No. Date Revised by Item Description
* V0.0 2011/12/10 涛行天下 ... ....
***************************************************************************************/
void Main(void)
{
U8 count_num = 0;
char *mode;
int i;
U8 key;
U32 mpll_val = 0 ;
//U32 divn_upll = 0 ;
#if ADS10
// __rt_lib_init(); //for ADS 1.0
#endif
Port_Init();//端口初始化
Isr_Init();//中断初始化
i = 2 ; //don't use 100M!
//boot_params.cpu_clk.val = 3;
//确定频率
switch ( i )
{
case 0: //200
key = 12;
mpll_val = (92<<12)|(4<<4)|(1);
break;
case 1: //300
key = 13;
mpll_val = (67<<12)|(1<<4)|(1);
break;
case 2: //400
key = 14;
mpll_val = (92<<12)|(1<<4)|(1);
break;
case 3: //440!!!
key = 14;
mpll_val = (102<<12)|(1<<4)|(1);
break;
default:
key = 14;
mpll_val = (92<<12)|(1<<4)|(1);
break;
}
//init FCLK=400M, so change MPLL first
ChangeMPllValue((mpll_val>>12)&0xff, (mpll_val>>4)&0x3f, mpll_val&3);
ChangeClockDivider(key, 12);
cal_cpu_bus_clk();
consoleNum = 0; // Uart 1 select for debug.选择串口号
Uart_Init( 0,115200 );//初始化串口参数以及时钟源
Uart_Select( consoleNum );//选择串口号
Beep(2000, 100);//蜂鸣器
Uart_SendByte('');//打印信息
Uart_SendByte('H');
while(1)
{
Uart_SendByte(count_num);
Uart_SendByte(' ');
count_num ++;
Delay(500);
}

复制代码

;//呼叫主应用程序
b UART
UART
ldr r0, =GPHCON ;//设置RxD0,TxD0引脚
ldr r1, =0x2afaaa
str r1, [r0]
ldr r0, =GPHUP
ldr r1, =0x7ff
str r1, [r0] ; // The pull up function is disabled GPH[10:0]
ldr r0, =UFCON0 ;//禁用FIFO
ldr r1, =0x0
str r1, [r0]
ldr r0, =UMCON0 ;//禁用AFC
ldr r1, =0x0
str r1, [r0]
ldr r0, =ULCON0 ;//设置线寄存器
ldr r1, =0x3 ; //UART LINE CONFIG 正常模式,无奇偶校验,一个停止位,8个数据位
str r1, [r0]
ldr r0, =UCON0 ;//设置Uart0控制器
ldr r1, =0x245;//RX边沿触发,TX电平触发,禁用延时中断,使用RX 错误中断,正常操作模式,中断请求或表决模式
str r1, [r0]
ldr r0, =UBRDIV0 ;//设置波特率为115200
ldr r1, =0x1a ;//int(50700000 / 16 / 115200) - 1 = 26
str r1, [r0]
mov r1, #100
Delay
sub r1, r1, #0x1
bne Delay
;//开中断
ldr r0, =INTMSK
ldr r1, [r0]
and r1, r1, #0xefffffff
str r1, [r0]
MOV R5 , #127 ;//设置要打印的字符的个数
MOV R1 , #0x0 ;//设置要打印的字符
LOOP
LDR R3 , =UTRSTAT0
LDR R2 , [R3]
TST R2 ,#0x04 ;//判断发送缓冲区是否为空
BEQ LOOP ;//为空则执行下边的语句，不为空则跳转到LOOP
LDR R0 , =UTXH0
STR R1 ,[R0] ;//向数据缓冲区放置要发送的数据
ADD R1, R1, #1
SUB R5 ,R5, #0x01 ;//计数器减一
CMP R5 ,#0x0
BNE LOOP
LOOP2 B LOOP2

复制代码