uart0.c

新华龙单片机C8051F060的RS232通信程序

#include <c8051f060.h>                    // SFR declarations

//sfr16 RCAP3    = 0xCA;                 // Timer3 reload value
//sfr16 TMR3     = 0xCC;                 // Timer3 counter
#define SYSCLK   20500000
//#define SYSCLK 22118400  
                 // SYSCLK frequency in Hz
#define BAUDRATE 115200                  // Baud Rate for UART0

void SYSCLK_Init (void);
void UART0_Init (void);
void PORT_Init (void);
void UART0_ISR(void);
void uart();
unsigned int m=0;
char c;
unsigned int receivedbit=0;

void main (void)
{
    WDTCN = 0xde;                          // disable watchdog timer
	WDTCN = 0xad;

	SYSCLK_Init ();                        // initialize SYSCLK
	PORT_Init ();
    UART0_Init ();                         // initialize UART0
	EA = 1;
	ES0 = 1;
    while(1)                             // Done.
	{
	  uart();
	}
}
void uart()  //发送函数(返回s和feedback的值)
{
  int i;
  while(receivedbit==1)
  {
    ES0 = 0;
	EA = 0;        
    receivedbit=0;
    SBUF0=c;
    while(TI0==0);
	TI0=0; 
  }
   ES0 = 1;
   EA = 1;       
}
void UART0_ISR(void) interrupt 4  //接收中断
{
  //if(!TI0)
  if(RI0)   //接收中断
  {
	 RI0 = 0; 
	 c=SBUF0;
     receivedbit=1;
  }
  TI0=0;
}

/*void UART0_ISR(void) interrupt 4  //发送中断
{
  if(TI0)   //接收中断
  {
	 TI0=0;
     SBUF0=c;
  }
     
}*/
void PORT_Init (void)
{
   char old_SFRPAGE = SFRPAGE;
   SFRPAGE = CONFIG_PAGE;              // Switch to configuration page

   XBR0    = 0x04;                     // Enable UART0 on crossbar
   XBR1    = 0x00;
   XBR2    = 0x40;                     // Enable crossbar and weak pull-ups
   P0MDOUT |= 0x01;                    // enable Port0 outputs as push-pull

   SFRPAGE = old_SFRPAGE;              // restore SFRPAGE
}

void UART0_Init (void) 
{
   char old_SFRPAGE = SFRPAGE;
   SFRPAGE = UART0_PAGE;               // Switch to UART0 page

   SCON0   = 0x50;                     // SCON: mode 1, 8-bit UART, enable RX
   SSTA0 = 0x10;                       // Timer 1 generates UART0 baud rate and
                                       // UART0 baud rate divide by two disabled
   SFRPAGE = TIMER01_PAGE;             // Switch to Timer 0/1 page

   TMOD   = 0x20;                      // TMOD: timer 1, mode 2, 8-bit reload
   TH1    = -(SYSCLK/BAUDRATE/16);     // set Timer1 reload value for baudrate
   TR1    = 1;                         // start Timer1
   CKCON |= 0x10;                      // Timer1 uses SYSCLK as time base
   PCON  |= 0x80;                      // SMOD = 1
   //TI0=0;
   SFRPAGE = UART0_PAGE;               // Switch to UART0 page
   SFRPAGE = old_SFRPAGE;              // restore SFRPAGE
}

void SYSCLK_Init (void)
{
   char old_SFRPAGE = SFRPAGE;
   int i; 
   
   SFRPAGE = CONFIG_PAGE;              // Switch to Configuration Page
   OSCXCN = 0x67;                      // start external oscillator with
                                       // 22.1184MHz crystal on TB
   for (i=0; i <5000; i++) ;           // XTLVLD blanking interval (>1ms)

   while (!(OSCXCN & 0x80)) ;          // Wait for crystal osc. to settle
   RSTSRC = 0x04;                      // enable missing clock detector reset
   CLKSEL = 0x01;                      // change to external crystal
   OSCICN = 0x00;                      // disable internal oscillator
   SFRPAGE = old_SFRPAGE;              // restore SFRPAGE
}