[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;


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