serial.c

来自「我写的针对lpc2141的ucos源码」· C语言 代码 · 共 55 行

/******************************************************************************/
/* SERIAL.C: Low Level Serial Routines                                        */
/******************************************************************************/
/* This file is part of the uVision/ARM development tools.                    */
/* Copyright (c) 2005-2006 Keil Software. All rights reserved.                */
/* 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 this software.  */
/******************************************************************************/

//<<< Use Configuration Wizard in Context Menu >>>
#include <LPC21xx.H>                     /* LPC21xx definitions               */

#include "serial.h"

#define CR 0x0D


/* implementation of putchar (also used by printf function to output data)    */
int sendchar (int ch)  	 /* Write character to Serial Port    */
{                 

	if (ch == '\n')  {
		while (!(U0LSR & 0x20));
		U0THR = CR;                          /* output CR */
	}
	while (!(U0LSR & 0x20));
	return (U0THR = ch);
}


int getkey (void)  	/* Read character from Serial Port   */
{                     

  while (!(U0LSR & 0x01));

  return (U0RBR);
}

void serial_init()	 /* initialize the serial interface   */
{
	PINSEL0|=0X00000005;
	U0LCR = 0x83;                   /* 8 bits, no Parity, 1 Stop bit            */
//   <o>   Baudrate Selection
//				 <195=>	4800 bps
//               <97=> 9600 bps
//               <65=> 14400 bps
//               <49=> 19200 bps
//               <24=> 38400 bps
	U0DLL = 97;						/* 9600 Baud Rate @ 15MHz VPB Clock         */
	//U0DLL = 78;                     /* 9600 Baud Rate @ 12MHz VPB Clock         */
  	U0LCR = 0x03;                   /* DLAB = 0         					  */
}