uart.c

自己写的adi bf561的bootloader.实现最简单的串口和flash

#include <stdarg.h> 				//提供va_start()函数定义等
#include <stdio.h>					//提供文件操作等		
#include "..\system_cdefBF561.h"	//提供CPU寄存器映射定义
#include "uart.h"

//asm(".section L1_code");


unsigned char Uart_GetByte(void)
{
  unsigned char ch; 
  while(!(*pUART_LSR & DR))
    ;
  ch =  *pUART_RBR;   
  return ch;
}

unsigned char Uart_RecvClear(void)
{
    unsigned char ch;  
    ch =  *pUART_RBR;   
    return ch; 
    
}


void Uart_SendByte(unsigned char data)
{
   
   while(!(*pUART_LSR & THRE))
    ;
  *pUART_THR =  data;   
}

void Uart_SendData(char *pt , int len)
{
    int i;
    for(i=0; i<len;i++)
    {
           Uart_SendByte(*pt++); 
    }
}  

void Uart_SendString(char *pt)
{
    while(*pt)
        Uart_SendByte(*pt++);
}

void Uart_Printf(char *fmt,...)
{
    va_list ap;
    char string[256];

    va_start(ap,fmt);
    vsprintf(string,fmt,ap);
    Uart_SendString(string);
    va_end(ap);
}


int fprintf(FILE *stream, const char *fmt,  ...)
{
    va_list ap;
    char string[256];

    va_start(ap,fmt);
    vsprintf(string,fmt,ap);
    Uart_SendString(string);
    va_end(ap);
    return 0;    
    
}


int printf(const char *fmt,  ...)
{
    
    va_list ap;
    char string[256];

    va_start(ap,fmt);
    vsprintf(string,fmt,ap);
    Uart_SendString(string);
    va_end(ap);
    return 0;
}


void Uart_Init(int bps)
{
    unsigned int divisor;
	// First of all, enable UART clock. 
	*pUART_GCTL = UCEN;
	
	// Read period value and apply formula:  divisor = period/16/8
	// Write result to the two 8-bit DL registers (DLH:DLL).
	*pUART_LCR = DLAB;
	
	divisor = SYSCLK / bps / 16 ;
	*pUART_DLL = divisor;
	*pUART_DLH = divisor>>8;
	
	// Clear DLAB again and set UART frame to 8 bits, no parity, 1 stop bit. 
	// This may differ in other scenarious.
	*pUART_LCR = WLS(8);			
}