1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)clock.h 7.3 (Berkeley) 06/28/90 8 */ 9 10 #define SECDAY ((unsigned)(24*60*60)) /* seconds per day */ 11 #define SECYR ((unsigned)(365*SECDAY)) /* per common year */ 12 13 #define YRREF 1970 14 #define LEAPYEAR(year) ((year)%4==0) /* good till time becomes negative */ 15 16 /* 17 * Software clock is software interrupt level 8 18 */ 19 #define setsoftclock() mtpr(SIRR, 0x8) 20 21 /* 22 * To calculate value for interval timer register, we 23 * use the fact that 20512 yields a 60hz clock. 24 */ 25 #define hztocount(v) ((20512*60) / (v)) 26