int.c

日本著名的的嵌入式实时操作系统T-Kernel的源码及用户手册。

/*
 *----------------------------------------------------------------------
 *    T-Kernel
 *
 *    Copyright (C) 2004 by Ken Sakamura. All rights reserved.
 *    T-Kernel is distributed under the T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.01.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2004/6/28.
 *
 *----------------------------------------------------------------------
 */

/*
 *	@(#)int.c (libtk/SH7727)
 *
 *	Interrupt controller  
 */

#include <basic.h>
#include <tk/syslib.h>
#include <tk/sysdef.h>

/*
 * Clear IRQ interrupt request 
 */
EXPORT void ClearInt( INTVEC vector )
{
	UW	msk = 1 << IRQNO(vector);
	UW	irr;
	UW	imask;

	/* Disable interrupt */
	Asm("	stc	sr, r0	\n"
	"	stc	sr, %0	\n"
	"	or	%1, r0	\n"
	"	ldc	r0, sr	"
		: "=r"(imask)
		: "i"(SR_I(15))
		: "r0"
	);

	irr = in_b(IRR0);
	if ( (irr & msk) != 0 ) {
		/* Clear interrupt request */
		out_b(IRR0, irr ^ msk);
	}

	/* Restore interrupt status */
	Asm("	ldc	%0, sr" :: "r"(imask));
}