clksys_driver.c File Reference

XMEGA Clock System driver source file. More...

#include "clksys_driver.h"

Functions
void	CCPWrite (volatile uint8_t *address, uint8_t value)
	CCP write helper function written in assembly.

Detailed Description

XMEGA Clock System driver source file.

 This file contains the function implementations for the XMEGA Clock
 System driver.

 The driver is not intended for size and/or speed critical code, since
 most functions are just a few lines of code, and the function call
 overhead would decrease code performance. The driver is intended for
 rapid prototyping and documentation purposes for getting started with
 the XMEGA Clock System.

 For size and/or speed critical code, it is recommended to copy the
 function contents directly into your application instead of making
 a function call.

 Several functions use the following construct:
     "some_register = ... | (some_parameter ? SOME_BIT_bm : 0) | ..."
 Although the use of the ternary operator ( if ? then : else ) is
 discouraged, in some occasions the operator makes it possible to
 write pretty clean and neat code. In this driver, the construct is
 used to set or not set a configuration bit based on a boolean input
 parameter, such as the "some_parameter" in the example above.

Application note:

AVR1003: Using the XMEGA Clock System

Documentation

For comprehensive code documentation, supported compilers, compiler settings and supported devices see readme.html

Author

Atmel Corporation: http://www.atmel.com
Support email: avr@a.nosp@m.tmel.nosp@m..com

Revision:

2771

Date:

2009-09-11 11:54:26 +0200 (fr, 11 sep 2009)

Copyright (c) 2008, Atmel Corporation All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

1. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

1. The name of ATMEL may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Function Documentation

void CCPWrite	(	volatile uint8_t *	address,
		uint8_t	value
	)

CCP write helper function written in assembly.

This function is written in assembly because of the timecritial operation of writing to the registers.

Parameters

address	A pointer to the address to write to.
value	The value to put in to the register.