serial.c

深圳英蓓特公司LPC23XX开发板配套光盘示例程序。

/*----------------------------------------------------------------------------
 *      Name:    serial.c
 *      Purpose: serial port handling
 *      Version: V1.00
 *----------------------------------------------------------------------------
 *      This file is part of the uVision/ARM development tools.
 *      This software may only be used under the terms of a valid, current,
 *      end user licence from KEIL for a compatible version of KEIL software
 *      development tools. Nothing else gives you the right to use it.
 *
 *      Copyright (c) 2005-2007 Keil Software.
 *---------------------------------------------------------------------------*/

#include "type.h"
#include <LPC23xx.H>                                  /* LPC23xx definitions */
#include "serial.h"

#define UART1                            /* Use UART 1  */

#ifdef UART0                             /* If UART 0 is used */
  #define UxFCR  U0FCR
  #define UxFDR  U0FDR
  #define UxLCR  U0LCR
  #define UxDLL  U0DLL
  #define UxDLM  U0DLM
  #define UxLSR  U0LSR
  #define UxMSR  U0MSR
  #define UxTHR  U0THR
  #define UxRBR  U0RBR
#elif defined(UART1)                     /* If UART 1 is used */
  #define UxFCR  U1FCR
  #define UxFDR  U1FDR
  #define UxLCR  U1LCR
  #define UxDLL  U1DLL
  #define UxDLM  U1DLM
  #define UxLSR  U1LSR
  #define UxMSR  U1MSR
  #define UxTHR  U1THR
  #define UxRBR  U1RBR
#endif

/*----------------------------------------------------------------------------
  initialize the buffer
 *---------------------------------------------------------------------------*/
void buf_Init (buf_t *buf, char *buffer) {
  buf->in  = 0;
  buf->out = 0;
  buf->buf = buffer;
}
 
/*----------------------------------------------------------------------------
  put a character into the buffer
 *---------------------------------------------------------------------------*/
BOOL buf_Put (buf_t *buf, char c) {
  int next;

  next = (buf->in + 1) % SER_BUF_SIZE;   /* check if space is available */
  if (next == buf->out) {                /* buffer full */
	return (FALSE);
  }

  buf->buf[buf->in] = c;
  buf->in = next;

  return (TRUE);
}


/*----------------------------------------------------------------------------
  get a character from the buffer
 *---------------------------------------------------------------------------*/
BOOL buf_Get (buf_t *buf, char *c) {
  int next;

  if (buf->in == buf->out) {                   /* check if data is available */
    return (FALSE);
  }

  next = (buf->out + 1) % SER_BUF_SIZE;

  *c = buf->buf[buf->out];
  buf->out = next;

  return (TRUE);
}


/*----------------------------------------------------------------------------
  check if space is in the buffer
 *---------------------------------------------------------------------------*/
int buf_Free (buf_t *buf) {
  int used;

  used = (SER_BUF_SIZE + buf->in - buf->out) % SER_BUF_SIZE;
  
  return (SER_BUF_SIZE - 1 - used);
}


/*----------------------------------------------------------------------------
  set the line coding
 *---------------------------------------------------------------------------*/
void ser_SetLineCoding (DWORD baudrate, BYTE databits, BYTE parity, BYTE stopbits) {
  BYTE  lcr_p, lcr_s, lcr_d;
  DWORD dll;

  switch (databits) {
    case 5:                              /* 5 Data bits   */
      lcr_d = 0x00;
    break;
    case 6:                              /* 6 Data bits   */
      lcr_d = 0x01;
    break;
    case 7:                              /* 7 Data bits   */
      lcr_d = 0x02;
    break;
    case 8:                              /* 8 Data bits   */
    default:
      lcr_d = 0x03;
    break;
  }

  switch (stopbits) {
    case 1:                              /* 1,5 Stop bits */
    case 2:                              /* 2   Stop bits */
      lcr_s = 0x04;
    break;
    case 0:                              /* 1   Stop bit  */
    default:
      lcr_s = 0x00;
    break;
  }

  switch (parity) {
    case 1:                              /* Parity Odd    */
      lcr_p = 0x08;
    break;
    case 2:                              /* Parity Even   */
      lcr_p = 0x18;
    break;
    case 3:                              /* Parity Mark   */
      lcr_p = 0x28;
    break;
    case 4:                              /* Parity Space  */
      lcr_p = 0x38;
    break;
    case 0:                              /* Parity None   */
    default:
      lcr_p = 0x00;
    break;
  }

  /* Note that the pclk is 24,0 MHz.  (48.0 MHz / 2)         */
  /* 24 MHz PCLK generates also rates for 115200, 57600 baud */
  dll = ((24000000UL / 16UL) ) / baudrate;

  UxFDR = 0x00;                          /* Fractional divider not used      */
  UxLCR = 0x80 | lcr_d | lcr_p | lcr_s;  /* Data bits, Parity,   Stop bit    */
  UxDLL = dll;                           /* Baud Rate @ 24 MHZ PCLK          */
  UxDLM = (dll >> 8);                    /* High divisor latch               */
  UxLCR = 0x00 | lcr_d | lcr_p | lcr_s;  /* DLAB = 0                         */
}


/*----------------------------------------------------------------------------
  initialize the serial interface
 *---------------------------------------------------------------------------*/
void ser_Init (void) {                   /* Initialize Serial Interface      */

  #ifdef UART0
    PINSEL0 |= 0x00000050;               /* Enable TxD0 and RxD0             */
  #elif defined (UART1)
    PINSEL0 |= 0x40000000;               /* Enable TxD1                      */
    PINSEL1 |= 0x00000001;               /* Enable RxD1                      */
  #endif

  ser_SetLineCoding (9600, 8, 0, 0);     /* set the initial LineCoding       */ 
}


/*----------------------------------------------------------------------------
  read the line status register
 *---------------------------------------------------------------------------*/
unsigned char ser_GetLSR (void) {
  return (UxLSR);
}


/*----------------------------------------------------------------------------
  read the modem status register
 *---------------------------------------------------------------------------*/
unsigned char ser_GetMSR (void) {
  return (UxMSR);
}


/*----------------------------------------------------------------------------
  read a character from serial interface
 *---------------------------------------------------------------------------*/
int ser_GetChar (void) {

  while (!(UxLSR & 0x01));

  return (UxRBR);
}


/*----------------------------------------------------------------------------
  put a caracter to the serial interface
 *---------------------------------------------------------------------------*/
int ser_PutChar (int ch) {

  if (ch == '\n')  {
	while (!(U0LSR & 0x20));
	UxTHR = '\r';                          /* output CR */
  }
  while (!(UxLSR & 0x20));

  return (UxTHR = ch);
}


/*----------------------------------------------------------------------------
  put a string to the serial interface
 *---------------------------------------------------------------------------*/
int ser_PutString (const char *s) {

  while (*s) {
    ser_PutChar(*s++);
  }
  ser_PutChar('\n');

  return (TRUE);
}


/*----------------------------------------------------------------------------
  check if a character is available at the serial interface
 *---------------------------------------------------------------------------*/
BOOL ser_AvailChar (void) {

  if ((UxLSR & 0x01) == 1)
    return (TRUE);
  else
    return (FALSE);
}