uart.c

mp4的源码,主要包括loader,usb driver,mp3 decoder,jpeg decoder,mpeg decoder部分.引导部分是基于arm9的s3c2410,部分代码未经过完善.

/*---------------------------------------------------------------------------------
Project           :  Test for 2410
Author            :  [e-mail]
Creation Date     :  04-04-15
Revision          :  None 
----------------------------------------------------------------------------------*/



#define  UART_G
#include "2410addr.h"


static int  WhichUart=0;
uint  		WaitCount = 0 ; 

extern  uchar  Updating, Loading  ; 	//?

void Uart_Init(int pclk,int baud)
{
    int i;
    
    if(pclk == 0)
    pclk    = PCLK;
    rUFCON0 = 0x0;   //UART channel 0 FIFO control register, FIFO disable
    rUFCON1 = 0x0;   //UART channel 1 FIFO control register, FIFO disable
    rUFCON2 = 0x0;   //UART channel 2 FIFO control register, FIFO disable
    rUMCON0 = 0x0;   //UART chaneel 0 MODEM control register, AFC disable
    rUMCON1 = 0x0;   //UART chaneel 1 MODEM control register, AFC disable
    
//UART0
    rULCON0 = 0x3;   //Line control register : Normal,No parity,1 stop,8 bits
     //    [10]       [9]     [8]        [7]        [6]      [5]         [4]           [3:2]        [1:0]
     // Clock Sel,  Tx Int,  Rx Int, Rx Time Out, Rx err, Loop-back, Send break,  Transmit Mode, Receive Mode
     //     0          1       0    ,     0          1        0           0     ,       01          01
     //   PCLK       Level    Pulse    Disable    Generate  Normal      Normal        Interrupt or Polling
    rUCON0  = 0x245;                        // Control register
    rUBRDIV0=( (int)(pclk/16./115200) -1 );   //Baud rate divisior register 0    
    
//UART1
    rULCON1 = 0x3;
    rUCON1  = 0x245;
    rUBRDIV1=( (int)(pclk/16./115200) -1 );
    
//UART2
    rULCON2 = 0x3;
    rUCON2  = 0x245;
    rUBRDIV2=( (int)(pclk/16./115200) -1 );    

    for(i=0;i<100;i++);
}

//===================================================================
void Uart_Select(int ch)
{
    WhichUart = ch;
}


//=====================================================================
char Uart_Get_Char(void)
{
    if(WhichUart==0)
    {       
        while(!(rUTRSTAT0 & 0x1))
        {
           if( Updating == 0 ) 
           { 
             WaitCount ++ ;

             if( WaitCount > 0x5FFFF ){ Loading = TRUE  ;  return 0 ; }

           }       
             
        }                     
        return RdURXH0();
    }
    else if(WhichUart==1)
    {       
        while(!(rUTRSTAT1 & 0x1)); //Receive data ready
        return RdURXH1();
    }
    else if(WhichUart==2)
    {
        while(!(rUTRSTAT2 & 0x1)); //Receive data ready
        return RdURXH2();
    }
}

//====================================================================
void Uart_Get_String(char *string)
{
    char *string2 = string;
    char c;
    while((c = Uart_Get_Char())!='\r')
    {
        if(c=='\b')
        {
            if( (int)string2 < (int)string )
            {
                Uart_Printf("\b \b");
                string--;
            }
        }
        else 
        {
            *string++ = c;
            Uart_SendByte(c);
        }
    }
    *string='\0';
    Uart_SendByte('\n');
}

//=====================================================================
void Uart_Send_Byte( char data)
{
    if(WhichUart==0)
    {
        if(data=='\n')
        {
            while(!(rUTRSTAT0 & 0x2));
            Delay(10);                 //because the slow response of hyper_terminal 
            WrUTXH0('\r');
        }
        while(!(rUTRSTAT0 & 0x2));   //Wait until THR is empty.
        Delay(5);
        WrUTXH0(data);
    }
    else if(WhichUart==1)
    {
        if(data=='\n')
        {
            while(!(rUTRSTAT1 & 0x2));
            Delay(10);                 //because the slow response of hyper_terminal 
            rUTXH1 = '\r';
        }
        while(!(rUTRSTAT1 & 0x2));   //Wait until THR is empty.
        Delay(10);
        rUTXH1 = data;
    }   
    else if(WhichUart==2)
    {
        if(data=='\n')
        {
            while(!(rUTRSTAT2 & 0x2));
            Delay(10);                 //because the slow response of hyper_terminal 
            rUTXH2 = '\r';
        }
        while(!(rUTRSTAT2 & 0x2));   //Wait until THR is empty.
        Delay(10);
        rUTXH2 = data;
    }       
}               

//====================================================================
void Uart_Send_String(char *pt)
{
    while(*pt)
        Uart_Send_Byte(*pt++);
}

//=====================================================================
//If you don't use vsprintf(), the code size is reduced very much.
void Uart_Printf(char *fmt,...)
{
    va_list ap;
    char string[256];

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



void Send_To_Byte( uchar data ) 
{
   if(WhichUart==0)
    {
        if(data=='\n')
        {
            while(!(rUTRSTAT0 & 0x2));
            Delay(10);                 //because the slow response of hyper_terminal 
            WrUTXH0('\r');
        }
        while(!(rUTRSTAT0 & 0x2));   //Wait until THR is empty.
        Delay(10);
        WrUTXH0(data);
    }

}