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/* timer_isr()
*
* This routine provides the ISR for the MC68230 timer on the Motorola
* IDP board. The timer is set up to generate an interrupt at maximum
* intervals.
*
* Code modified by Doug McBride, Colorado Space Grant College
* countdown should be loaded automatically
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* $Id$
*/
#include "asm.h"
BEGIN_CODE
.set TSR, 0x00c0106B | base address of PIT register "TSR"
PUBLIC (timerisr)
SYM (timerisr):
movb #1,TSR | acknowledge interrupt
addql #1, SYM (Ttimer_val) | increment timer value
rte
END_CODE
END
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