include/clockdomain.h

/* DOSBox-X clock domain class.
 * The clock domain implementation allows DOSBox-X to accurately
 * track time in clocks instead of less precise floating point
 * intervals, and to more accurately emulate hardware in terms of
 * the reference clock.
 *
 * (C) 2014 Jonathan Campbell */

#include <stdint.h>
#include <assert.h>
#include <math.h>

#include <string>
#include <vector>
#include <list>

#ifndef DOSBOX_CLOCKDOMAIN_H
#define DOSBOX_CLOCKDOMAIN_H

#include "dosbox.h"
/* this code contains support for existing DOSBox code that uses PIC_AddEvent, etc. callbacks */
#include "pic.h"

class ClockDomain {
public:
        ClockDomain() {
                freq = 0;
                freq_div = 1;
        counter = 0;
        }
        ClockDomain(unsigned long long freq_new) {
                freq = freq_new;
                freq_div = 1;
        counter = 0;
        }
        /* we allow non-integer frequencies as integer fractions.
         * example: 33.3333333...MHz as 100,000,000Hz / 3 */
        ClockDomain(unsigned long long freq_new,unsigned long long div) {
                freq = freq_new;
                freq_div = div;
        counter = 0;
        }
public:
        void set_name(const char *s) {
                name = s;
        }
        void set_frequency(unsigned long long freq_new,unsigned long long div_new=1) {
                counter = 0;
                freq = freq_new;
                freq_div = div_new;
        }
        const char *get_name() {
                return name.c_str();
        }
public:
        /* NTS: Slave clock rules:
         *       - Must have the same "freq" value as master
         *       - Do not set clock time by floating point time (only the toplevel clocks in the tree should do that)
         *       - Must rebase at the same reference time as the master
         *       - Must maintain time according to master time divided by master's clock divider */
        unsigned long long              freq,freq_div;  /* frequency of clock as integer ratio */
        unsigned long long              counter;        /* in units of freq */
        std::string                     name;
};

#endif //DOSBOX_CLOCKDOMAIN_H