ATmega8自适应波特率的实现(软件包)_AVR单片机

ATmega8自适应波特率的实现(软件包)

点击数：7327 次录入时间：03-04 11:33:32 整理：http://www.55dianzi.com AVR单片机

Project Name: Method of auto-baudrate for ATmega8
Date:         2006-June-01
Author:       Eighth Army
System Crystal: Internal 8MHz by RC
Compiler Reversion: IAR for AVR 412A
Additional information:
  1 Embedded system startup baudrate is 2400bps.
  2 Higher baud rate of PC is not recommend.(Ref. BAUD_RATE_ARRAY specifICation)
  3 After slaver returns "AA 55",it means the baud rate set completed.
  4 File name:Main.c
Debugging data:  AA 55
*******************************************************************/

＃i nclude <iom8.h>
＃i nclude "INCLUDES.H"
＃i nclude "CONSTANTS.H"
＃i nclude "FUNCTIONS.H"
＃i nclude "VARIABLES.H"

const uchar BAUD_RATE_ARRAY[12] = {
                    /* Embedded startup value -> PC     Repeat Times */
  0xA0,0X01,        /* 2400 */
  0xCF,0x00,        /* 4800                   -> 4800   5 Times */
  0x67,0x00,        /* 9600                   -> 9600   7 Times */
  0x33,0x00,        /* 19200                  -> 19200  10 Times */
  0x19,0x00,        /* 38400                  -> 38400  30 Times */
  0x10,0x00         /* 57600                  -> 57600  17 Times */
  };

/****** Super Loop body *******************************************/
void main( void ){
InitialSystem();
while( 1 )
  {
  if( !( ucStatusProgram & bSET_BAUD ))
    {
    if( uiTenor & bRECEIVED )
      {
      uiTenor &= ~bRECEIVED;
      if( ! Judge( &uCCommunicatorBuffer[0] ) )
        {
        ExchangeBaudRate( ( uchar *)&BAUD_RATE_ARRAY[ ucSearch ] );
        ucSearch += 2;
        }
      else
        {
        PORTB |= ( 1 << INDICATE );
        ucStatusProgram |= bSET_BAUD;
        TransmitData( ucCommunicatorBuffer, 2 );
        }
      }
    }
  else
    {
    if( uiTenor & bRECEIVED )
      {
      uiTenor &= ~bRECEIVED;
      PORTB ^= ( 1 << INDICATE );
      TransmitData( ucCommunicatorBuffer, ucCommunicatorBuffer[1] );
      }
    }
  }
}
/*******************************************************************
@Fn: InitialSystem()
@Br: Initialization of system
@Pa: None
@Rt: None
*******************************************************************/
void InitialSystem( void ){
_DI();
ConfigTimerSystem();
ConfigParallelPort();
ConfigSerialPort();
ucSearch = 0;
_EI();
}
/*******************************************************************
@Fn: Delay_mS()
@Br: Non-Interrupt one milliSecond delay
@Pa: uiMS
@Rt: None
*******************************************************************/
void Delay_mS( uint uiMS ){
ulong ulMultiplex;
ulMultiplex = ( ulong )uiMS * ( ulong )8;
while( ulMultiplex-- );
}
/*******************************************************************
@Fn: ConfigSerialPort()
@Br: Configuration of MCU
@Pa: None
@Rt: None
*******************************************************************/
void ConfigSerialPort( void ){
UCSRA = ( 1 << U2X );                       /* Double baud rate enabLED */
UBRRH = 0x01;
UBRRL = 0xA0;                               /* 2400bps @ 8MHz */
UCSRB = ( 1 << RXCIE ) | ( 1 << TXEN ) | ( 1 << RXEN );       /*Enable the Rxc & RX & TX interrupt*/
UCSRC = ( 1 << URSEL ) | ( 1 << UCSZ1 ) | ( 1 << UCSZ0 );     /*8 bit Data*/
}
/*******************************************************************
@Fn: ConfigTimerSystem()
@Br: Configuration of TIMER on system
@Pa: None
@Rt: None
*******************************************************************/
void ConfigTimerSystem( void ){
TCCR0 = ( 1 << CS02 ) + ( 1 << CS00 );        /* clk/1024 */
TCNT0 = 0X00;