[picodrive.git] / pico / cd / mcd.c

/*
 * PicoDrive
 * (C) notaz, 2007,2013
 *
 * This work is licensed under the terms of MAME license.
 * See COPYING file in the top-level directory.
 */

#include "../pico_int.h"
#include "../sound/ym2612.h"

extern unsigned char formatted_bram[4*0x10];

static unsigned int mcd_m68k_cycle_mult;
static unsigned int mcd_m68k_cycle_base;
static unsigned int mcd_s68k_cycle_base;

void (*PicoMCDopenTray)(void) = NULL;
void (*PicoMCDcloseTray)(void) = NULL;


PICO_INTERNAL void PicoInitMCD(void)
{
  SekInitS68k();
}

PICO_INTERNAL void PicoExitMCD(void)
{
}

PICO_INTERNAL void PicoPowerMCD(void)
{
  int fmt_size;

  SekCycleCntS68k = SekCycleAimS68k = 0;

  fmt_size = sizeof(formatted_bram);
  memset(Pico_mcd->prg_ram,    0, sizeof(Pico_mcd->prg_ram));
  memset(Pico_mcd->word_ram2M, 0, sizeof(Pico_mcd->word_ram2M));
  memset(Pico_mcd->pcm_ram,    0, sizeof(Pico_mcd->pcm_ram));
  memset(Pico_mcd->bram, 0, sizeof(Pico_mcd->bram));
  memcpy(Pico_mcd->bram + sizeof(Pico_mcd->bram) - fmt_size,
    formatted_bram, fmt_size);
  memset(Pico_mcd->s68k_regs, 0, sizeof(Pico_mcd->s68k_regs));
  memset(&Pico_mcd->pcm, 0, sizeof(Pico_mcd->pcm));
  memset(&Pico_mcd->m, 0, sizeof(Pico_mcd->m));

  cdc_init();
  gfx_init();

  // cold reset state (tested)
  Pico_mcd->m.state_flags = PCD_ST_S68K_RST;
  Pico_mcd->m.busreq = 2;     // busreq on, s68k in reset
  Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode, m68k access
  memset(Pico_mcd->bios + 0x70, 0xff, 4);
}

void pcd_soft_reset(void)
{
  elprintf(EL_CD, "cd: soft reset");

  Pico_mcd->m.s68k_pend_ints = 0;
  cdc_reset();
  cdd_reset();
#ifdef _ASM_CD_MEMORY_C
  //PicoMemResetCDdecode(1); // don't have to call this in 2M mode
#endif

  memset(&Pico_mcd->s68k_regs[0x38], 0, 9);
  Pico_mcd->s68k_regs[0x38+9] = 0x0f;  // default checksum

  pcd_event_schedule_s68k(PCD_EVENT_CDC, 12500000/75);

  // TODO: test if register state/timers change
}

PICO_INTERNAL int PicoResetMCD(void)
{
  // reset button doesn't affect MCD hardware

  // use Pico.sv.data for RAM cart
  if (PicoOpt & POPT_EN_MCD_RAMCART) {
    if (Pico.sv.data == NULL)
      Pico.sv.data = calloc(1, 0x12000);
  }
  else if (Pico.sv.data != NULL) {
    free(Pico.sv.data);
    Pico.sv.data = NULL;
  }
  Pico.sv.start = Pico.sv.end = 0; // unused

  return 0;
}

static void SekRunM68kOnce(void)
{
  int cyc_do;
  pevt_log_m68k_o(EVT_RUN_START);

  if ((cyc_do = Pico.t.m68c_aim - Pico.t.m68c_cnt) > 0) {
    Pico.t.m68c_cnt += cyc_do;

#if defined(EMU_C68K)
    PicoCpuCM68k.cycles = cyc_do;
    CycloneRun(&PicoCpuCM68k);
    Pico.t.m68c_cnt -= PicoCpuCM68k.cycles;
#elif defined(EMU_M68K)
    Pico.t.m68c_cnt += m68k_execute(cyc_do) - cyc_do;
#elif defined(EMU_F68K)
    Pico.t.m68c_cnt += fm68k_emulate(cyc_do, 0) - cyc_do;
#endif
  }

  SekCyclesLeft = 0;

  SekTrace(0);
  pevt_log_m68k_o(EVT_RUN_END);
}

static void SekRunS68k(unsigned int to)
{
  int cyc_do;

  SekCycleAimS68k = to;
  if ((cyc_do = SekCycleAimS68k - SekCycleCntS68k) <= 0)
    return;

  if (SekShouldInterrupt())
    Pico_mcd->m.s68k_poll_a = 0;

  SekCycleCntS68k += cyc_do;
#if defined(EMU_C68K)
  PicoCpuCS68k.cycles = cyc_do;
  CycloneRun(&PicoCpuCS68k);
  SekCycleCntS68k -= PicoCpuCS68k.cycles;
#elif defined(EMU_M68K)
  m68k_set_context(&PicoCpuMS68k);
  SekCycleCntS68k += m68k_execute(cyc_do) - cyc_do;
  m68k_set_context(&PicoCpuMM68k);
#elif defined(EMU_F68K)
  g_m68kcontext = &PicoCpuFS68k;
  SekCycleCntS68k += fm68k_emulate(cyc_do, 0) - cyc_do;
  g_m68kcontext = &PicoCpuFM68k;
#endif
}

static void pcd_set_cycle_mult(void)
{
  // ~1.63 for NTSC, ~1.645 for PAL
  if (Pico.m.pal)
    mcd_m68k_cycle_mult = ((12500000ull << 16) / (50*313*488));
  else
    mcd_m68k_cycle_mult = ((12500000ull << 16) / (60*262*488)) + 1;
}

unsigned int pcd_cycles_m68k_to_s68k(unsigned int c)
{
  return (long long)c * mcd_m68k_cycle_mult >> 16;
}

/* events */
static void pcd_cdc_event(unsigned int now)
{
  // 75Hz CDC update
  cdd_update();

  /* check if a new CDD command has been processed */
  if (!(Pico_mcd->s68k_regs[0x4b] & 0xf0))
  {
    /* reset CDD command wait flag */
    Pico_mcd->s68k_regs[0x4b] = 0xf0;

    if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN4) {
      elprintf(EL_INTS|EL_CD, "s68k: cdd irq 4");
      SekInterruptS68k(4);
    }
  }

  pcd_event_schedule(now, PCD_EVENT_CDC, 12500000/75);
}

static void pcd_int3_timer_event(unsigned int now)
{
  if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN3) {
    elprintf(EL_INTS|EL_CD, "s68k: timer irq 3");
    SekInterruptS68k(3);
  }

  if (Pico_mcd->s68k_regs[0x31] != 0)
    pcd_event_schedule(now, PCD_EVENT_TIMER3,
      Pico_mcd->s68k_regs[0x31] * 384);
}

static void pcd_dma_event(unsigned int now)
{
  cdc_dma_update();
}

typedef void (event_cb)(unsigned int now);

/* times are in s68k (12.5MHz) cycles */
unsigned int pcd_event_times[PCD_EVENT_COUNT];
static unsigned int event_time_next;
static event_cb *pcd_event_cbs[PCD_EVENT_COUNT] = {
  pcd_cdc_event,            // PCD_EVENT_CDC
  pcd_int3_timer_event,     // PCD_EVENT_TIMER3
  gfx_update,               // PCD_EVENT_GFX
  pcd_dma_event,            // PCD_EVENT_DMA
};

void pcd_event_schedule(unsigned int now, enum pcd_event event, int after)
{
  unsigned int when;

  when = now + after;
  if (when == 0) {
    // event cancelled
    pcd_event_times[event] = 0;
    return;
  }

  when |= 1;

  elprintf(EL_CD, "cd: new event #%u %u->%u", event, now, when);
  pcd_event_times[event] = when;

  if (event_time_next == 0 || CYCLES_GT(event_time_next, when))
    event_time_next = when;
}

void pcd_event_schedule_s68k(enum pcd_event event, int after)
{
  if (SekCyclesLeftS68k > after)
    SekEndRunS68k(after);

  pcd_event_schedule(SekCyclesDoneS68k(), event, after);
}

static void pcd_run_events(unsigned int until)
{
  int oldest, oldest_diff, time;
  int i, diff;

  while (1) {
    oldest = -1, oldest_diff = 0x7fffffff;

    for (i = 0; i < PCD_EVENT_COUNT; i++) {
      if (pcd_event_times[i]) {
        diff = pcd_event_times[i] - until;
        if (diff < oldest_diff) {
          oldest_diff = diff;
          oldest = i;
        }
      }
    }

    if (oldest_diff <= 0) {
      time = pcd_event_times[oldest];
      pcd_event_times[oldest] = 0;
      elprintf(EL_CD, "cd: run event #%d %u", oldest, time);
      pcd_event_cbs[oldest](time);
    }
    else if (oldest_diff < 0x7fffffff) {
      event_time_next = pcd_event_times[oldest];
      break;
    }
    else {
      event_time_next = 0;
      break;
    }
  }

  if (oldest != -1)
    elprintf(EL_CD, "cd: next event #%d at %u",
      oldest, event_time_next);
}

int pcd_sync_s68k(unsigned int m68k_target, int m68k_poll_sync)
{
  #define now SekCycleCntS68k
  unsigned int s68k_target;
  unsigned int target;

  target = m68k_target - mcd_m68k_cycle_base;
  s68k_target = mcd_s68k_cycle_base +
    ((unsigned long long)target * mcd_m68k_cycle_mult >> 16);

  elprintf(EL_CD, "s68k sync to %u, %u->%u",
    m68k_target, now, s68k_target);

  if (Pico_mcd->m.busreq != 1) { /* busreq/reset */
    SekCycleCntS68k = SekCycleAimS68k = s68k_target;
    pcd_run_events(m68k_target);
    return 0;
  }

  while (CYCLES_GT(s68k_target, now)) {
    if (event_time_next && CYCLES_GE(now, event_time_next))
      pcd_run_events(now);

    target = s68k_target;
    if (event_time_next && CYCLES_GT(target, event_time_next))
      target = event_time_next;

    SekRunS68k(target);
    if (m68k_poll_sync && Pico_mcd->m.m68k_poll_cnt == 0)
      break;
  }

  return s68k_target - now;
  #undef now
}

#define pcd_run_cpus_normal pcd_run_cpus
//#define pcd_run_cpus_lockstep pcd_run_cpus

static void SekSyncM68k(void);

void pcd_run_cpus_normal(int m68k_cycles)
{
  Pico.t.m68c_aim += m68k_cycles;
  if (SekShouldInterrupt() || Pico_mcd->m.m68k_poll_cnt < 12)
    Pico_mcd->m.m68k_poll_cnt = 0;
  else if (Pico_mcd->m.m68k_poll_cnt >= 16) {
    int s68k_left = pcd_sync_s68k(Pico.t.m68c_aim, 1);
    if (s68k_left <= 0) {
      elprintf(EL_CDPOLL, "m68k poll [%02x] x%d @%06x",
        Pico_mcd->m.m68k_poll_a, Pico_mcd->m.m68k_poll_cnt, SekPc);
      Pico.t.m68c_cnt = Pico.t.m68c_aim;
      return;
    }
    Pico.t.m68c_cnt = Pico.t.m68c_aim - (s68k_left * 40220 >> 16);
  }

  while (CYCLES_GT(Pico.t.m68c_aim, Pico.t.m68c_cnt)) {
    SekRunM68kOnce();
    if (Pico_mcd->m.need_sync) {
      Pico_mcd->m.need_sync = 0;
      pcd_sync_s68k(Pico.t.m68c_cnt, 0);
    }
  }
}

void pcd_run_cpus_lockstep(int m68k_cycles)
{
  unsigned int target = Pico.t.m68c_aim + m68k_cycles;
  do {
    Pico.t.m68c_aim += 8;
    SekSyncM68k();
    pcd_sync_s68k(Pico.t.m68c_aim, 0);
  } while (CYCLES_GT(target, Pico.t.m68c_aim));

  Pico.t.m68c_aim = target;
}

#define PICO_CD
#define CPUS_RUN(m68k_cycles) \
  pcd_run_cpus(m68k_cycles)

#include "../pico_cmn.c"


void pcd_prepare_frame(void)
{
  pcd_set_cycle_mult();

  // need this because we can't have direct mapping between
  // master<->slave cycle counters because of overflows
  mcd_m68k_cycle_base = Pico.t.m68c_aim;
  mcd_s68k_cycle_base = SekCycleAimS68k;
}

PICO_INTERNAL void PicoFrameMCD(void)
{
  PicoFrameStart();

  pcd_prepare_frame();
  PicoFrameHints();
}

void pcd_state_loaded(void)
{
  unsigned int cycles;
  int diff;

  pcd_set_cycle_mult();
  pcd_state_loaded_mem();

  memset(Pico_mcd->pcm_mixbuf, 0, sizeof(Pico_mcd->pcm_mixbuf));
  Pico_mcd->pcm_mixbuf_dirty = 0;
  Pico_mcd->pcm_mixpos = 0;
  Pico_mcd->pcm_regs_dirty = 1;

  // old savestates..
  cycles = pcd_cycles_m68k_to_s68k(Pico.t.m68c_aim);
  diff = cycles - SekCycleAimS68k;
  if (diff < -1000 || diff > 1000) {
    SekCycleCntS68k = SekCycleAimS68k = cycles;
  }
  if (pcd_event_times[PCD_EVENT_CDC] == 0) {
    pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_CDC, 12500000/75);

    if (Pico_mcd->s68k_regs[0x31])
      pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_TIMER3,
        Pico_mcd->s68k_regs[0x31] * 384);
  }

  diff = cycles - Pico_mcd->pcm.update_cycles;
  if ((unsigned int)diff > 12500000/50)
    Pico_mcd->pcm.update_cycles = cycles;

  // reschedule
  event_time_next = 0;
  pcd_run_events(SekCycleCntS68k);
}

// vim:shiftwidth=2:ts=2:expandtab
Commit	Line	Data
	1	/*
	2	* PicoDrive
	3	* (C) notaz, 2007,2013
	4	*
	5	* This work is licensed under the terms of MAME license.
	6	* See COPYING file in the top-level directory.
	7	*/
	8
	9	#include "../pico_int.h"
	10	#include "../sound/ym2612.h"
	11
	12	extern unsigned char formatted_bram[4*0x10];
	13
	14	static unsigned int mcd_m68k_cycle_mult;
	15	static unsigned int mcd_m68k_cycle_base;
	16	static unsigned int mcd_s68k_cycle_base;
	17
	18	void (*PicoMCDopenTray)(void) = NULL;
	19	void (*PicoMCDcloseTray)(void) = NULL;
	20
	21
	22	PICO_INTERNAL void PicoInitMCD(void)
	23	{
	24	SekInitS68k();
	25	}
	26
	27	PICO_INTERNAL void PicoExitMCD(void)
	28	{
	29	}
	30
	31	PICO_INTERNAL void PicoPowerMCD(void)
	32	{
	33	int fmt_size;
	34
	35	SekCycleCntS68k = SekCycleAimS68k = 0;
	36
	37	fmt_size = sizeof(formatted_bram);
	38	memset(Pico_mcd->prg_ram, 0, sizeof(Pico_mcd->prg_ram));
	39	memset(Pico_mcd->word_ram2M, 0, sizeof(Pico_mcd->word_ram2M));
	40	memset(Pico_mcd->pcm_ram, 0, sizeof(Pico_mcd->pcm_ram));
	41	memset(Pico_mcd->bram, 0, sizeof(Pico_mcd->bram));
	42	memcpy(Pico_mcd->bram + sizeof(Pico_mcd->bram) - fmt_size,
	43	formatted_bram, fmt_size);
	44	memset(Pico_mcd->s68k_regs, 0, sizeof(Pico_mcd->s68k_regs));
	45	memset(&Pico_mcd->pcm, 0, sizeof(Pico_mcd->pcm));
	46	memset(&Pico_mcd->m, 0, sizeof(Pico_mcd->m));
	47
	48	cdc_init();
	49	gfx_init();
	50
	51	// cold reset state (tested)
	52	Pico_mcd->m.state_flags = PCD_ST_S68K_RST;
	53	Pico_mcd->m.busreq = 2; // busreq on, s68k in reset
	54	Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode, m68k access
	55	memset(Pico_mcd->bios + 0x70, 0xff, 4);
	56	}
	57
	58	void pcd_soft_reset(void)
	59	{
	60	elprintf(EL_CD, "cd: soft reset");
	61
	62	Pico_mcd->m.s68k_pend_ints = 0;
	63	cdc_reset();
	64	cdd_reset();
	65	#ifdef _ASM_CD_MEMORY_C
	66	//PicoMemResetCDdecode(1); // don't have to call this in 2M mode
	67	#endif
	68
	69	memset(&Pico_mcd->s68k_regs[0x38], 0, 9);
	70	Pico_mcd->s68k_regs[0x38+9] = 0x0f; // default checksum
	71
	72	pcd_event_schedule_s68k(PCD_EVENT_CDC, 12500000/75);
	73
	74	// TODO: test if register state/timers change
	75	}
	76
	77	PICO_INTERNAL int PicoResetMCD(void)
	78	{
	79	// reset button doesn't affect MCD hardware
	80
	81	// use Pico.sv.data for RAM cart
	82	if (PicoOpt & POPT_EN_MCD_RAMCART) {
	83	if (Pico.sv.data == NULL)
	84	Pico.sv.data = calloc(1, 0x12000);
	85	}
	86	else if (Pico.sv.data != NULL) {
	87	free(Pico.sv.data);
	88	Pico.sv.data = NULL;
	89	}
	90	Pico.sv.start = Pico.sv.end = 0; // unused
	91
	92	return 0;
	93	}
	94
	95	static void SekRunM68kOnce(void)
	96	{
	97	int cyc_do;
	98	pevt_log_m68k_o(EVT_RUN_START);
	99
	100	if ((cyc_do = Pico.t.m68c_aim - Pico.t.m68c_cnt) > 0) {
	101	Pico.t.m68c_cnt += cyc_do;
	102
	103	#if defined(EMU_C68K)
	104	PicoCpuCM68k.cycles = cyc_do;
	105	CycloneRun(&PicoCpuCM68k);
	106	Pico.t.m68c_cnt -= PicoCpuCM68k.cycles;
	107	#elif defined(EMU_M68K)
	108	Pico.t.m68c_cnt += m68k_execute(cyc_do) - cyc_do;
	109	#elif defined(EMU_F68K)
	110	Pico.t.m68c_cnt += fm68k_emulate(cyc_do, 0) - cyc_do;
	111	#endif
	112	}
	113
	114	SekCyclesLeft = 0;
	115
	116	SekTrace(0);
	117	pevt_log_m68k_o(EVT_RUN_END);
	118	}
	119
	120	static void SekRunS68k(unsigned int to)
	121	{
	122	int cyc_do;
	123
	124	SekCycleAimS68k = to;
	125	if ((cyc_do = SekCycleAimS68k - SekCycleCntS68k) <= 0)
	126	return;
	127
	128	if (SekShouldInterrupt())
	129	Pico_mcd->m.s68k_poll_a = 0;
	130
	131	SekCycleCntS68k += cyc_do;
	132	#if defined(EMU_C68K)
	133	PicoCpuCS68k.cycles = cyc_do;
	134	CycloneRun(&PicoCpuCS68k);
	135	SekCycleCntS68k -= PicoCpuCS68k.cycles;
	136	#elif defined(EMU_M68K)
	137	m68k_set_context(&PicoCpuMS68k);
	138	SekCycleCntS68k += m68k_execute(cyc_do) - cyc_do;
	139	m68k_set_context(&PicoCpuMM68k);
	140	#elif defined(EMU_F68K)
	141	g_m68kcontext = &PicoCpuFS68k;
	142	SekCycleCntS68k += fm68k_emulate(cyc_do, 0) - cyc_do;
	143	g_m68kcontext = &PicoCpuFM68k;
	144	#endif
	145	}
	146
	147	static void pcd_set_cycle_mult(void)
	148	{
	149	// ~1.63 for NTSC, ~1.645 for PAL
	150	if (Pico.m.pal)
	151	mcd_m68k_cycle_mult = ((12500000ull << 16) / (50313488));
	152	else
	153	mcd_m68k_cycle_mult = ((12500000ull << 16) / (60262488)) + 1;
	154	}
	155
	156	unsigned int pcd_cycles_m68k_to_s68k(unsigned int c)
	157	{
	158	return (long long)c * mcd_m68k_cycle_mult >> 16;
	159	}
	160
	161	/* events */
	162	static void pcd_cdc_event(unsigned int now)
	163	{
	164	// 75Hz CDC update
	165	cdd_update();
	166
	167	/* check if a new CDD command has been processed */
	168	if (!(Pico_mcd->s68k_regs[0x4b] & 0xf0))
	169	{
	170	/* reset CDD command wait flag */
	171	Pico_mcd->s68k_regs[0x4b] = 0xf0;
	172
	173	if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN4) {
	174	elprintf(EL_INTS\|EL_CD, "s68k: cdd irq 4");
	175	SekInterruptS68k(4);
	176	}
	177	}
	178
	179	pcd_event_schedule(now, PCD_EVENT_CDC, 12500000/75);
	180	}
	181
	182	static void pcd_int3_timer_event(unsigned int now)
	183	{
	184	if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN3) {
	185	elprintf(EL_INTS\|EL_CD, "s68k: timer irq 3");
	186	SekInterruptS68k(3);
	187	}
	188
	189	if (Pico_mcd->s68k_regs[0x31] != 0)
	190	pcd_event_schedule(now, PCD_EVENT_TIMER3,
	191	Pico_mcd->s68k_regs[0x31] * 384);
	192	}
	193
	194	static void pcd_dma_event(unsigned int now)
	195	{
	196	cdc_dma_update();
	197	}
	198
	199	typedef void (event_cb)(unsigned int now);
	200
	201	/* times are in s68k (12.5MHz) cycles */
	202	unsigned int pcd_event_times[PCD_EVENT_COUNT];
	203	static unsigned int event_time_next;
	204	static event_cb *pcd_event_cbs[PCD_EVENT_COUNT] = {
	205	pcd_cdc_event, // PCD_EVENT_CDC
	206	pcd_int3_timer_event, // PCD_EVENT_TIMER3
	207	gfx_update, // PCD_EVENT_GFX
	208	pcd_dma_event, // PCD_EVENT_DMA
	209	};
	210
	211	void pcd_event_schedule(unsigned int now, enum pcd_event event, int after)
	212	{
	213	unsigned int when;
	214
	215	when = now + after;
	216	if (when == 0) {
	217	// event cancelled
	218	pcd_event_times[event] = 0;
	219	return;
	220	}
	221
	222	when \|= 1;
	223
	224	elprintf(EL_CD, "cd: new event #%u %u->%u", event, now, when);
	225	pcd_event_times[event] = when;
	226
	227	if (event_time_next == 0 \|\| CYCLES_GT(event_time_next, when))
	228	event_time_next = when;
	229	}
	230
	231	void pcd_event_schedule_s68k(enum pcd_event event, int after)
	232	{
	233	if (SekCyclesLeftS68k > after)
	234	SekEndRunS68k(after);
	235
	236	pcd_event_schedule(SekCyclesDoneS68k(), event, after);
	237	}
	238
	239	static void pcd_run_events(unsigned int until)
	240	{
	241	int oldest, oldest_diff, time;
	242	int i, diff;
	243
	244	while (1) {
	245	oldest = -1, oldest_diff = 0x7fffffff;
	246
	247	for (i = 0; i < PCD_EVENT_COUNT; i++) {
	248	if (pcd_event_times[i]) {
	249	diff = pcd_event_times[i] - until;
	250	if (diff < oldest_diff) {
	251	oldest_diff = diff;
	252	oldest = i;
	253	}
	254	}
	255	}
	256
	257	if (oldest_diff <= 0) {
	258	time = pcd_event_times[oldest];
	259	pcd_event_times[oldest] = 0;
	260	elprintf(EL_CD, "cd: run event #%d %u", oldest, time);
	261	pcd_event_cbs[oldest](time);
	262	}
	263	else if (oldest_diff < 0x7fffffff) {
	264	event_time_next = pcd_event_times[oldest];
	265	break;
	266	}
	267	else {
	268	event_time_next = 0;
	269	break;
	270	}
	271	}
	272
	273	if (oldest != -1)
	274	elprintf(EL_CD, "cd: next event #%d at %u",
	275	oldest, event_time_next);
	276	}
	277
	278	int pcd_sync_s68k(unsigned int m68k_target, int m68k_poll_sync)
	279	{
	280	#define now SekCycleCntS68k
	281	unsigned int s68k_target;
	282	unsigned int target;
	283
	284	target = m68k_target - mcd_m68k_cycle_base;
	285	s68k_target = mcd_s68k_cycle_base +
	286	((unsigned long long)target * mcd_m68k_cycle_mult >> 16);
	287
	288	elprintf(EL_CD, "s68k sync to %u, %u->%u",
	289	m68k_target, now, s68k_target);
	290
	291	if (Pico_mcd->m.busreq != 1) { /* busreq/reset */
	292	SekCycleCntS68k = SekCycleAimS68k = s68k_target;
	293	pcd_run_events(m68k_target);
	294	return 0;
	295	}
	296
	297	while (CYCLES_GT(s68k_target, now)) {
	298	if (event_time_next && CYCLES_GE(now, event_time_next))
	299	pcd_run_events(now);
	300
	301	target = s68k_target;
	302	if (event_time_next && CYCLES_GT(target, event_time_next))
	303	target = event_time_next;
	304
	305	SekRunS68k(target);
	306	if (m68k_poll_sync && Pico_mcd->m.m68k_poll_cnt == 0)
	307	break;
	308	}
	309
	310	return s68k_target - now;
	311	#undef now
	312	}
	313
	314	#define pcd_run_cpus_normal pcd_run_cpus
	315	//#define pcd_run_cpus_lockstep pcd_run_cpus
	316
	317	static void SekSyncM68k(void);
	318
	319	void pcd_run_cpus_normal(int m68k_cycles)
	320	{
	321	Pico.t.m68c_aim += m68k_cycles;
	322	if (SekShouldInterrupt() \|\| Pico_mcd->m.m68k_poll_cnt < 12)
	323	Pico_mcd->m.m68k_poll_cnt = 0;
	324	else if (Pico_mcd->m.m68k_poll_cnt >= 16) {
	325	int s68k_left = pcd_sync_s68k(Pico.t.m68c_aim, 1);
	326	if (s68k_left <= 0) {
	327	elprintf(EL_CDPOLL, "m68k poll [%02x] x%d @%06x",
	328	Pico_mcd->m.m68k_poll_a, Pico_mcd->m.m68k_poll_cnt, SekPc);
	329	Pico.t.m68c_cnt = Pico.t.m68c_aim;
	330	return;
	331	}
	332	Pico.t.m68c_cnt = Pico.t.m68c_aim - (s68k_left * 40220 >> 16);
	333	}
	334
	335	while (CYCLES_GT(Pico.t.m68c_aim, Pico.t.m68c_cnt)) {
	336	SekRunM68kOnce();
	337	if (Pico_mcd->m.need_sync) {
	338	Pico_mcd->m.need_sync = 0;
	339	pcd_sync_s68k(Pico.t.m68c_cnt, 0);
	340	}
	341	}
	342	}
	343
	344	void pcd_run_cpus_lockstep(int m68k_cycles)
	345	{
	346	unsigned int target = Pico.t.m68c_aim + m68k_cycles;
	347	do {
	348	Pico.t.m68c_aim += 8;
	349	SekSyncM68k();
	350	pcd_sync_s68k(Pico.t.m68c_aim, 0);
	351	} while (CYCLES_GT(target, Pico.t.m68c_aim));
	352
	353	Pico.t.m68c_aim = target;
	354	}
	355
	356	#define PICO_CD
	357	#define CPUS_RUN(m68k_cycles) \
	358	pcd_run_cpus(m68k_cycles)
	359
	360	#include "../pico_cmn.c"
	361
	362
	363	void pcd_prepare_frame(void)
	364	{
	365	pcd_set_cycle_mult();
	366
	367	// need this because we can't have direct mapping between
	368	// master<->slave cycle counters because of overflows
	369	mcd_m68k_cycle_base = Pico.t.m68c_aim;
	370	mcd_s68k_cycle_base = SekCycleAimS68k;
	371	}
	372
	373	PICO_INTERNAL void PicoFrameMCD(void)
	374	{
	375	PicoFrameStart();
	376
	377	pcd_prepare_frame();
	378	PicoFrameHints();
	379	}
	380
	381	void pcd_state_loaded(void)
	382	{
	383	unsigned int cycles;
	384	int diff;
	385
	386	pcd_set_cycle_mult();
	387	pcd_state_loaded_mem();
	388
	389	memset(Pico_mcd->pcm_mixbuf, 0, sizeof(Pico_mcd->pcm_mixbuf));
	390	Pico_mcd->pcm_mixbuf_dirty = 0;
	391	Pico_mcd->pcm_mixpos = 0;
	392	Pico_mcd->pcm_regs_dirty = 1;
	393
	394	// old savestates..
	395	cycles = pcd_cycles_m68k_to_s68k(Pico.t.m68c_aim);
	396	diff = cycles - SekCycleAimS68k;
	397	if (diff < -1000 \|\| diff > 1000) {
	398	SekCycleCntS68k = SekCycleAimS68k = cycles;
	399	}
	400	if (pcd_event_times[PCD_EVENT_CDC] == 0) {
	401	pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_CDC, 12500000/75);
	402
	403	if (Pico_mcd->s68k_regs[0x31])
	404	pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_TIMER3,
	405	Pico_mcd->s68k_regs[0x31] * 384);
	406	}
	407
	408	diff = cycles - Pico_mcd->pcm.update_cycles;
	409	if ((unsigned int)diff > 12500000/50)
	410	Pico_mcd->pcm.update_cycles = cycles;
	411
	412	// reschedule
	413	event_time_next = 0;
	414	pcd_run_events(SekCycleCntS68k);
	415	}
	416
	417	// vim:shiftwidth=2:ts=2:expandtab