uart1.c

来自「阿根廷教授编写的嵌入式internet的实验教程的高质量代码」· C语言 代码 · 共 83 行

/******************************************************************************************
   Uart1.c (v1.0)
-------------------------------------------------------------------------------------
This code is from the book:
"Embedded Internet: TCP/IP Basics, Implementation and Applications" by Sergio Scaglia
[Pearson Education, 2006 - ISBN: 0-32-130638-4]

This code is copyright (c) 2006 by Sergio Scaglia, and it may only be used for educational
purposes.  For commercial use, please contact me at [e-mail]
For more information and updates, please visit www.embeddedinternet.org
******************************************************************************************/

#include "sysClock.h"
#include "uart1.h"
#include <iolpc2129.h>
#include <stdio.h>

#define CR          0x0D

#define IN_BUF_LEN	2048                // Must be Power of 2 ...
static char in_buf[IN_BUF_LEN];
static unsigned short inbuf_in_ptr=0;
static unsigned short inbuf_out_ptr=0;

#if ((IN_BUF_LEN & (IN_BUF_LEN - 1)) != 0)
#error IN_BUF_LEN must be power of 2!
#endif

void uart1_irq(void) {					   // Generate Interrupt
volatile char IIR;

  while (((IIR = U1IIR) & 0x01) == 0) {
    if ((inbuf_in_ptr - inbuf_out_ptr) < IN_BUF_LEN) {
      in_buf[inbuf_in_ptr & (IN_BUF_LEN - 1)] = U1RBR;
      inbuf_in_ptr++;
    }
    else {
      printf("Error: Input Buffer exhausted! Increment IN_BUF_LEN\n");
      break;
    }
  }
  VICVectAddr = 0;                       // Acknowledge Interrupt
}


void UART1_init(unsigned int baud) {
  volatile char dummy;
  unsigned int divisor = (pClkFreq()/4) / (16 * baud);

  U1LCR = 0x83; /* 8 bit, 1 stop bit, no parity, enable DLAB */
  U1DLL = divisor & 0xFF;
  U1DLM = (divisor >> 8) & 0xFF;
  U1LCR &= ~0x80; /* Disable DLAB */
  PINSEL0 = (PINSEL0 & ~0xF0000) | 0x50000;
  U1FCR = 1;
  U1IER = 0;				        // Disable RDA interrupt
  VICVectAddr1 = (unsigned int)uart1_irq;      	// set interrupt vector in 1
  VICVectCntl1 = 0x20 | 7;               	// use it for UART 1 Interrupt
  VICIntEnable = 0x00000080;             	// Enable UART 1 Interrupt
  dummy = U1IIR;   			        // Read IrqID - Required to Get Interrupts Started
  U1IER = 1;       			        // Enable UART1 RX
}

void putchar1(int ch) {

  if (ch == '\n')  {
    while (!(U1LSR & 0x20));
    U1THR = CR;
  }
  while (!(U1LSR & 0x20));
  U1THR = ch;
}


int getchar1 (void) {

  if (inbuf_out_ptr < inbuf_in_ptr)
    return in_buf[(inbuf_out_ptr++) & (IN_BUF_LEN - 1)];
  else {
    return (-1);
  }	
}