f93x_uart0_stdio.c

芯科原厂所有c8051fxx程序的例子。

//-----------------------------------------------------------------------------
// F93x_UART0_STDIO.c
//-----------------------------------------------------------------------------
// Copyright 2007 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program demonstrates how to configure the C8051F930 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 jumpers are placed on J12 of the C8051F930 target board
//    that connect P0.4/TX to the RXD signal, P0.5/RX to the TXD signal,
//    and VDD/DC+ to VIO.
// 2) Connect a USB cable from the development board to a PC
// 3) Specify the target baudrate in the constant <BAUDRATE>.
// 4) Open Hyperterminal, or a similar program, and connect to the target
//    board's USB port (virtual com port).
// 5) Download and execute code to an 'F930 target board.
//
//
// Target:         C8051F93x-C8051F92x
// Tool chain:     Generic
// Command Line:   None
//
// Release 1.1
//    - Updated to be compatible with SDCC. (FB)
//    - 9 NOV 2007
//
// Release 1.0
//    -Initial Revision (FB)
//    -14 AUG 2007
//

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

#include <compiler_defs.h>
#include <C8051F930_defs.h>            // SFR declarations
#include <stdio.h>

//-----------------------------------------------------------------------------
// Global CONSTANTS
//-----------------------------------------------------------------------------

#define SYSCLK      24500000           // SYSCLK frequency in Hz
#define BAUDRATE      230400           // Baud rate of UART in bps

//-----------------------------------------------------------------------------
// Function PROTOTYPES
//-----------------------------------------------------------------------------

void SYSCLK_Init (void);
void UART0_Init (void);
void PORT_Init (void);

//-----------------------------------------------------------------------------
// Generic UART definitions to support both Keil and SDCC
//-----------------------------------------------------------------------------

#ifdef SDCC
#include <sdcc_stdio.h>
#endif

char *GETS (char *, unsigned int);

#ifdef __C51__
#define GETS gets
#endif

#ifdef SDCC
#include <sdcc_stdio.c>
#endif


//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------

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

   PCA0MD &= ~0x40;                    // WDTE = 0 (clear watchdog timer
                                       // enable)

   PORT_Init();                        // Initialize Port I/O
   SYSCLK_Init ();                     // Initialize Oscillator
   UART0_Init();                       // Initialize UART0

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

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

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// Configure the Crossbar and GPIO ports.
//
// P0.4   digital   push-pull    UART TX
// P0.5   digital   open-drain   UART RX
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
   P0MDOUT |= 0x10;                    // Enable UTX as push-pull output
   XBR0    = 0x01;                     // Enable UART on P0.4(TX) and P0.5(RX)
   XBR2    = 0x40;                     // Enable crossbar and weak pull-ups
}

//-----------------------------------------------------------------------------
// SYSCLK_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This routine initializes the system clock to use the internal precision 
// oscillator at its maximum frequency and enables the missing clock 
// detector.
// 
//-----------------------------------------------------------------------------

void SYSCLK_Init (void)
{
   
   OSCICN |= 0x80;                     // Enable the precision internal osc.
   
   RSTSRC = 0x06;                      // Enable missing clock detector and
                                       // leave VDD Monitor enabled.

   CLKSEL = 0x00;                      // Select precision internal osc. 
                                       // divided by 1 as the system clock
   
}

//-----------------------------------------------------------------------------
// 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;
   #elif (SYSCLK/BAUDRATE/2/256 < 4) 
      TH1 = -(SYSCLK/BAUDRATE/2/4);
      CKCON &= ~0x0B;                  // T1M = 0; SCA1:0 = 01
      CKCON |=  0x01;
   #elif (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;
   #endif

   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
//-----------------------------------------------------------------------------