tacho.c

3 phase motor driver source code with freescale MCU

/*
 * Project:		 	CLOSED LOOP 3-PHASE AC DRIVE
 *
 * Microcontroller: Motorola MC68HC908MR24 
 *
 * Module:			TACHO.C
 * Revision/Date:	2.0 / February 2000 
 * Description:		This routine is 3rd level ISR responding to 
 *					Input Capture interrupt. it calculates time 
 * 					between 2 subsequent IC events. Also provides
 *	 				IC filter.
 *					Input:	IC generated by speed sensor 
 *					Output:	time between 2 subsequent IC events	
 *
 * Compiler:		Hiware08 Compiler
 *
 * Author:			Radim VISINKA
 * Company:			MOTOROLA SPS
 *					Roznov System Application Laboratory 
 *					Roznov pod Radhostem, Czech Republic 
 *
 * ===================================================================
 *
 * Copyright (c):	MOTOROLA Inc.,1998, All rights reserved.
 *
 * ====================================================================
 * THIS SOFTWARE IS PROVIDED BY MOTOROLA RSAL "AS IS" AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL MOTOROLA RSAL OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 */


/* DEFINITION_START */


/* Include Header Files */
#include <mr24io.h>
#include "CONST.H"			/* file contains global constants and
							   definitions */

/* Assembler Subroutine Definitions */

/* Constant Definitions */

/* Global Variables (External) - 8 bit */

/* Global Variables (External) - 16 bit */
extern unsigned int Tacho_pulses; 

/* Local Variables - 8 bit */

/* Local Variables - 16 bit */
unsigned int Old_capture = 0;
			  

/* DEFINITION_END */


void tacho (void)
	{
	Tacho_pulses = TACH3 - Old_capture;	/* calculate the time between 
											2 rising edges */
	Old_capture = TACH3; 
	TASC3 &= 0x7f;					/* clear Timer A3 Interrupt flag */	  	
	}