uart.c

usbport-sl811usb主控器芯片usb程序实现

// AT90USB/usart_drv.c
// Basic output routines for USART, adapted to Atmels AT90USB microcontrollers
// Based on AT90USB Datasheet (7593D-AVR-07/06), chapter 18 and examples from
// http://www.mikrocontroller.net/articles/AVR-GCC-Tutorial and
// http://www.roboternetz.de/wissen/index.php/UART_mit_avr-gcc
// S. Salewski 27-FEB-2007

#include <avr/io.h>
#include "defines.h"
#include "uart.h"
#include "macros.h"

#ifndef NOUART

#define Wait_USART_Ready() while (!(UCSR1A & (1<<UDRE1)))
#define UART_UBRR (F_CPU/(16L*USART_BAUD)-1) 

// initialize USART, 8N1 mode
void
USART_Init(void)
{
  UBRR1 = 51; // at 8MHz 9600 baud
  UCSR1C = (1<<UCSZ10) | (1<<UCSZ11);
  UCSR1B = (1<<TXEN1);
}

void
USART_WriteChar(char c)
{
  Wait_USART_Ready();
  UDR1 = c;
}

void
USART_WriteHex(unsigned char c)
{
  unsigned char nibble;
  nibble = (c >> 4);
  if (nibble < 10) nibble += '0'; else nibble += ('A'-10);
  Wait_USART_Ready();
  UDR1 = nibble;
  nibble = (c & 0x0F);
  if (nibble < 10) nibble += '0'; else nibble += ('A'-10);
  Wait_USART_Ready();
  UDR1 = nibble;
}

void
USART_WriteHexW(uint16_t w)
{
  USART_WriteHex(MSB(w));
  USART_WriteHex(LSB(w));
}


void UARTWrite(char *s){
  USART_WriteString(s);
}

void
USART_WriteString(char *s)
{
  while (*s) USART_WriteChar(*s++);
}

void
USART_NewLine(void)
{
  Wait_USART_Ready();
  UDR1 = '\r';
  Wait_USART_Ready();
  UDR1 = '\n';
}

#endif