write.c File Reference

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Detailed Description

System-specific implementation of the __write function used by the standard library.

• Compiler: IAR EWAVR32
• Supported devices: All AVR32 devices with a USART module can be used.
• AppNote:

Author:

Atmel Corporation: http://www.atmel.com
Support and FAQ: http://support.atmel.no/

Definition in file write.c.

#include <yfuns.h>
#include <avr32/io.h>
#include "usart.h"

Go to the source code of this file.

Functions
size_t	__write (int handle, const unsigned char *buffer, size_t size)
	Writes a number of bytes, at most size, from the memory area pointed to by buffer.
Variables
_STD_BEGIN __no_init volatile avr32_usart_t *volatile	stdio_usart_base
	Pointer to the base of the USART module instance to use for stdio.

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Function Documentation

size_t __write	(	int	handle,
		const unsigned char *	buffer,
		size_t	size
	)

Writes a number of bytes, at most size, from the memory area pointed to by buffer.

If buffer is zero then __write performs flushing of internal buffers, if any. In this case, handle can be -1 to indicate that all handles should be flushed.

Parameters:

	handle	File handle to write to.
	buffer	Pointer to buffer to read bytes to write from.
	size	Number of bytes to write.

Returns:

The number of bytes written, or _LLIO_ERROR on failure.

Definition at line 75 of file write.c.

References stdio_usart_base.

{
  size_t nChars = 0;

  if (buffer == 0)
  {
    // This means that we should flush internal buffers.
    return 0;
  }

  // This implementation only writes to stdout and stderr.
  // For all other file handles, it returns failure.
  if (handle != _LLIO_STDOUT && handle != _LLIO_STDERR)
  {
    return _LLIO_ERROR;
  }

  for (; size != 0; --size)
  {
    if (usart_putchar(stdio_usart_base, *buffer++) < 0)
    {
      return _LLIO_ERROR;
    }

    ++nChars;
  }

  return nChars;
}

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Variable Documentation

_STD_BEGIN __no_init volatile avr32_usart_t* volatile stdio_usart_base

Pointer to the base of the USART module instance to use for stdio.

Definition at line 59 of file write.c.

Referenced by __low_level_init(), __read(), and __write().