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rf_etimer.h revision 1.3 
      1 /*	$NetBSD: rf_etimer.h,v 1.3 1999/02/05 00:06:11 oster Exp $	*/
      2 /*
      3  * Copyright (c) 1995 Carnegie-Mellon University.
      4  * All rights reserved.
      5  *
      6  * Author: Mark Holland
      7  *
      8  * Permission to use, copy, modify and distribute this software and
      9  * its documentation is hereby granted, provided that both the copyright
     10  * notice and this permission notice appear in all copies of the
     11  * software, derivative works or modified versions, and any portions
     12  * thereof, and that both notices appear in supporting documentation.
     13  *
     14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17  *
     18  * Carnegie Mellon requests users of this software to return to
     19  *
     20  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21  *  School of Computer Science
     22  *  Carnegie Mellon University
     23  *  Pittsburgh PA 15213-3890
     24  *
     25  * any improvements or extensions that they make and grant Carnegie the
     26  * rights to redistribute these changes.
     27  */
     28 
     29 /* rf_etimer.h -- header file for code related to accurate timing
     30  * This code currently assumes that the elapsed time between START_TIMER
     31  * and START_TIMER is less than the period of the cycle counter.  This
     32  * means the events you want to time must be less than:
     33  *        clock speed               max time
     34  *        ----------                --------
     35  *           175 MHz                 24 sec
     36  *           150 MHz                 28 sec
     37  *           125 MHz                 34 sec
     38  *
     39  *
     40  */
     41 
     42 
     43 #ifndef _RF__RF_TIMER_H_
     44 #define _RF__RF_TIMER_H_
     45 
     46 #include "rf_options.h"
     47 
     48 extern unsigned int rpcc(void);
     49 #define rf_read_cycle_counter rpcc
     50 
     51 #define RF_DEF_TIMER_MAX_VAL            0xFFFFFFFF
     52 
     53 typedef struct RF_EtimerVal_s {
     54 	unsigned ccnt;		/* cycle count */
     55 }       RF_EtimerVal_t;
     56 
     57 struct RF_Etimer_s {
     58 	RF_EtimerVal_t st;
     59 	RF_EtimerVal_t et;
     60 	unsigned long ticks;	/* elapsed time in ticks */
     61 };
     62 
     63 extern long rf_timer_max_val;
     64 extern long rf_timer_ticks_per_second;
     65 extern unsigned long rf_timer_ticks_per_usec;
     66 
     67 #define RF_ETIMER_TICKS2US(_tcks_)  ( (_tcks_) / rf_timer_ticks_per_usec )
     68 #define RF_ETIMER_START(_t_)  { (_t_).st.ccnt = rf_read_cycle_counter(); }
     69 #define RF_ETIMER_STOP(_t_)   { (_t_).et.ccnt = rf_read_cycle_counter(); }
     70 #define RF_ETIMER_EVAL(_t_) { \
     71 	if ((_t_).st.ccnt < (_t_).et.ccnt) \
     72 		(_t_).ticks = (_t_).et.ccnt - (_t_).st.ccnt; \
     73 	else \
     74 		(_t_).ticks = rf_timer_max_val - ((_t_).st.ccnt - (_t_).et.ccnt); \
     75 }
     76 
     77 #define RF_ETIMER_VAL_TICKS(_t_)  ((_t_).ticks)
     78 #define RF_ETIMER_VAL_US(_t_)      (RF_ETIMER_TICKS2US((_t_).ticks))
     79 #define RF_ETIMER_VAL_MS(_t_)      (RF_ETIMER_TICKS2US((_t_).ticks)/1000)
     80 
     81 
     82 #endif				/* !_RF__RF_TIMER_H_ */
     83