f53xa_uart0_stdio_poll.c

C8051F52xA_53xA型单片机的串口驱动源码

//-----------------------------------------------------------------------------
// F53xA_UART0_STDIO_Poll.c
//-----------------------------------------------------------------------------
// Copyright 2007 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program demonstrates how to configure the C8051F530A to use routines
// in STDIO.h to write to and read from the UART interface.  The program
// reads a character using the STDIO routine getkey(), outputs that character
// to the screen, and then outputs the ASCII hex value of that character.
//
//
// How To Test:
//
// 1) Ensure that the UART TX/RX jumpers are placed on HDR3 of the
//    F530A target board to connect the P0.4 pin to the TX signal, and P0.5 to
//    the RX signal.
// 2) Connect a USB cable from P1 on the TB to the PC.
// 3) Specify the target baudrate in the constant <BAUDRATE>.
// 4) Open Hyperterminal, or a similar terminalprogram, and connect to the
//    target board's serial port using <BAUDRATE> 8-N-1.
// 5) Download the code to device A on an 'F530A target board.
// 6) Run the code.
//
//
// Target:         C8051F52xA/F53xA (C8051F530A TB)
// Tool chain:     Keil C51 7.50 / Keil EVAL C51
// Command Line:   None
//
// Release 1.1
//    -Updated for 'F530A TB (TP)
//    -31 JAN 2008
//
// Release 1.0
//    -Initial Revision (SM)
//    -13 JUN 2007
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------

#include "compiler_defs.h"
#include "C8051F520A_defs.h"
#include <stdio.h>

//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------

#define SYSCLK             24500000    // Internal oscillator frequency in Hz
#define BAUDRATE             115200    // Baud rate of UART in bps

//-----------------------------------------------------------------------------
// Function Prototypes
//-----------------------------------------------------------------------------

void PCA0_Init (void);
void Oscillator_Init (void);
void Port_Init (void);
void UART0_Init (void);
void Init_Device (void);

//-----------------------------------------------------------------------------
// main() Routine
//-----------------------------------------------------------------------------
void main (void)
{
   unsigned char inputcharacter;       // Used to store character from UART

   Init_Device ();                     // Initializes hardware peripherals

   while (1)
   {
      printf ("\nEnter character: ");
      inputcharacter = getkey ();
      printf ("\nCharacter entered : %c",inputcharacter);
      printf ("\n     Value in Hex : %bx",inputcharacter);
   }
}

//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// PCA0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function disables the watchdog timer.
//
//-----------------------------------------------------------------------------
void PCA0_Init (void)
{
   PCA0MD &= ~0x40;                    // Disable the Watchdog Timer
   PCA0MD = 0x00;
}

//-----------------------------------------------------------------------------
// Oscillator_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function initializes the system clock to use the internal oscillator
// at 24.5 MHz.
//
//-----------------------------------------------------------------------------
void Oscillator_Init (void)
{
   OSCICN = 0x87;                      // Set the internal oscillator to
                                       // 24.5 MHz
}

//-----------------------------------------------------------------------------
// Port_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and GPIO ports.
//
// P0.4   digital   push-pull   (TX)
// P0.5   digital   open-drain  (RX)
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
    P0MDOUT   = 0x10;                  // Make TX push-pull
    XBR0      = 0x01;                  // Enable UART0 on the crossbar
    XBR1      = 0x40;                  // Enable the crossbar
}

//-----------------------------------------------------------------------------
// Init_Device
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// Calls all device initialization functions.
//
//-----------------------------------------------------------------------------
void Init_Device (void)
{
   PCA0_Init ();                       // Disable the Watchdog Timer first
   Oscillator_Init ();
   Port_Init ();
   UART0_Init ();
}

//-----------------------------------------------------------------------------
// UART0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// Configure the UART0 using Timer1, for <BAUDRATE> and 8-N-1.
//-----------------------------------------------------------------------------
void UART0_Init (void)
{
   SCON0 = 0x10;                       // SCON0: 8-bit variable bit rate
                                       //        level of STOP bit is ignored
                                       //        RX enabled
                                       //        ninth bits are zeros
                                       //        clear RI0 and TI0 bits
   if (SYSCLK/BAUDRATE/2/256 < 1) {
      TH1 = -(SYSCLK/BAUDRATE/2);
      CKCON &= ~0x0B;                  // T1M = 1; SCA1:0 = xx
      CKCON |=  0x08;
   } else if (SYSCLK/BAUDRATE/2/256 < 4) {
      TH1 = -(SYSCLK/BAUDRATE/2/4);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 01
      CKCON |=  0x01;
   } else if (SYSCLK/BAUDRATE/2/256 < 12) {
      TH1 = -(SYSCLK/BAUDRATE/2/12);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 00
   } else {
      TH1 = -(SYSCLK/BAUDRATE/2/48);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 10
      CKCON |=  0x02;
   }

   TL1 = TH1;                          // Init Timer1
   TMOD &= ~0xf0;                      // TMOD: timer 1 in 8-bit autoreload
   TMOD |=  0x20;
   TR1 = 1;                            // START Timer1
   TI0 = 1;                            // Indicate TX0 ready

}

//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------