xref: /csrg-svn/sys/tahoe/include/clock.h (revision 44526)
134407Skarels /*
234407Skarels  * Copyright (c) 1988 Regents of the University of California.
334407Skarels  * All rights reserved.
434407Skarels  *
5*44526Sbostic  * %sccs.include.redist.c%
634407Skarels  *
7*44526Sbostic  *	@(#)clock.h	7.3 (Berkeley) 06/28/90
834407Skarels  */
924011Ssam 
1024011Ssam #define	SECDAY		((unsigned)(24*60*60))		/* seconds per day */
1124011Ssam #define	SECYR		((unsigned)(365*SECDAY))	/* per common year */
1224011Ssam 
1324011Ssam #define	YRREF		1970
1424011Ssam #define	LEAPYEAR(year)	((year)%4==0)	/* good till time becomes negative */
1524011Ssam 
1624011Ssam /*
1724011Ssam  * Software clock is software interrupt level 8
1824011Ssam  */
1925678Ssam #define	setsoftclock()	mtpr(SIRR, 0x8)
2030257Ssam 
2130257Ssam /*
2230257Ssam  * To calculate value for interval timer register, we
2330257Ssam  * use the fact that 20512 yields a 60hz clock.
2430257Ssam  */
2530257Ssam #define	hztocount(v)	((20512*60) / (v))
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