/* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS 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 THE REGENTS OR 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. * * @(#)timerreg.h 8.1 (Berkeley) 6/11/93 * * from: $Header: timerreg.h,v 1.7 92/11/26 03:05:09 leres Exp $ (LBL) */ /* * Sun-4c counter/timer registers. The timers are implemented within * the cache chip (!). The counter and limit fields below could be * defined as: * * struct { * u_int t_limit:1, // limit reached * t_usec:21, // counter value in microseconds * t_mbz:10; // always zero * }; * * but this is more trouble than it is worth. * * These timers work in a rather peculiar fashion. Most clock counters * run to 0 (as, e.g., on the VAX, where the ICR counts up to 0 from a * large unsigned number). On the Sun-4c, it counts up to a limit. But * for some reason, when it reaches the limit, it resets to 1, not 0. * Thus, if the limit is set to 4, the counter counts like this: * * 1, 2, 3, 1, 2, 3, ... * * and if we want to divide by N we must set the limit register to N+1. */ #ifndef LOCORE struct timer { int t_counter; /* counter reg */ int t_limit; /* limit reg */ }; struct timerreg { struct timer t_c10; /* counter that interrupts at ipl 10 */ struct timer t_c14; /* counter that interrupts at ipl 14 */ }; #endif #define TMR_LIMIT 0x80000000 /* counter reached its limit */ #define TMR_SHIFT 10 /* shift to obtain microseconds */ #define TMR_MASK 0x1fffff /* 21 bits */ /* Compute a limit that causes the timer to fire every n microseconds. */ #define tmr_ustolim(n) (((n) + 1) << TMR_SHIFT) #include <sparc/sparc/vaddrs.h> #define TIMERREG ((volatile struct timerreg *)TIMERREG_VA)