/*
* common code for base/cd/32x
* (C) notaz, 2007-2009,2013
+ * (C) irixxxx, 2020-2024
*
* This work is licensed under the terms of MAME license.
* See COPYING file in the top-level directory.
#endif
// sync m68k to Pico.t.m68c_aim
-static void SekSyncM68k(void)
+static void SekExecM68k(int cyc_do)
{
- int cyc_do;
- pprof_start(m68k);
- pevt_log_m68k_o(EVT_RUN_START);
-
- while ((cyc_do = Pico.t.m68c_aim - Pico.t.m68c_cnt) > 0) {
- Pico.t.m68c_cnt += cyc_do;
+ Pico.t.m68c_cnt += cyc_do;
#if defined(EMU_C68K)
- PicoCpuCM68k.cycles = cyc_do;
- CycloneRun(&PicoCpuCM68k);
- Pico.t.m68c_cnt -= PicoCpuCM68k.cycles;
+ 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;
+ 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;
+ Pico.t.m68c_cnt += fm68k_emulate(&PicoCpuFM68k, cyc_do, 0) - cyc_do;
#endif
- }
-
SekCyclesLeft = 0;
+}
+
+static int SekSyncM68k(int once)
+{
+ int cyc_do;
+
+ pprof_start(m68k);
+ pevt_log_m68k_o(EVT_RUN_START);
+
+ while ((cyc_do = Pico.t.m68c_aim - Pico.t.m68c_cnt) > 0) {
+ // the Z80 CPU is stealing some bus cycles from the 68K main CPU when
+ // accessing the main bus. Account for these by shortening the time
+ // the 68K CPU runs.
+ int z80_buscyc = Pico.t.z80_buscycles >> (4+(~Pico.m.scanline & 1));
+ // NB the Z80 isn't fast enough to steal more than half the bandwidth.
+ // the fastest would be POP cc which takes 10+~3.3*2 z-cyc (~35 cyc) for a
+ // 16 bit value, but 68k is only blocked for ~16 cyc for the 2 bus cycles.
+ if (z80_buscyc > cyc_do/2)
+ z80_buscyc = cyc_do/2;
+ SekExecM68k(cyc_do - z80_buscyc);
+ Pico.t.m68c_cnt += z80_buscyc;
+ Pico.t.z80_buscycles -= z80_buscyc<<4;
+ if (once) break;
+ }
SekTrace(0);
pevt_log_m68k_o(EVT_RUN_END);
pprof_end(m68k);
+
+ return Pico.t.m68c_aim > Pico.t.m68c_cnt;
}
-static __inline void SekRunM68k(int cyc)
+static __inline void SekAimM68k(int cyc, int mult)
{
+ // refresh slowdown, for cart: 2 cycles every 128 - make this 1 every 64,
+ // for RAM: seems to be 0-3 every 128. Carts usually run from the cart
+ // area, but MCD games only use RAM, hence a different multiplier is needed.
+ // NB must be quite accurate, so handle fractions as well (c/f OutRunners)
+ int delay = (Pico.t.refresh_delay += cyc*mult) >> 14;
+ Pico.t.m68c_cnt += delay;
+ Pico.t.refresh_delay -= delay << 14;
Pico.t.m68c_aim += cyc;
- cyc = Pico.t.m68c_aim - Pico.t.m68c_cnt;
- if (cyc <= 0)
- return;
- Pico.t.m68c_cnt += cyc >> 6; // refresh slowdowns
- SekSyncM68k();
+}
+
+static __inline void SekRunM68k(int cyc)
+{
+ // TODO 0x100 would be 2 cycles/128, moreover far too sensitive
+ SekAimM68k(cyc, 0x108); // OutRunners, testpico, VDPFIFOTesting
+ SekSyncM68k(0);
+}
+
+static void SyncCPUs(unsigned int cycles)
+{
+ // sync cpus
+ if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80))
+ PicoSyncZ80(cycles);
+
+#ifdef PICO_CD
+ if (PicoIn.AHW & PAHW_MCD)
+ pcd_sync_s68k(cycles, 0);
+#endif
+#ifdef PICO_32X
+ p32x_sync_sh2s(cycles);
+#endif
}
static void do_hint(struct PicoVideo *pv)
pv->pending_ints |= 0x10;
if (pv->reg[0] & 0x10) {
elprintf(EL_INTS, "hint: @ %06x [%u]", SekPc, SekCyclesDone());
- SekInterrupt(4);
+ if (SekIrqLevel < pv->hint_irq)
+ SekInterrupt(pv->hint_irq);
}
}
-static void do_timing_hacks_as(struct PicoVideo *pv, int vdp_slots)
+static void do_timing_hacks_end(struct PicoVideo *pv)
{
- pv->lwrite_cnt += vdp_slots - Pico.m.dma_xfers * 2; // wrong *2
- if (pv->lwrite_cnt > vdp_slots)
- pv->lwrite_cnt = vdp_slots;
- else if (pv->lwrite_cnt < 0)
- pv->lwrite_cnt = 0;
- if (Pico.m.dma_xfers)
- SekCyclesBurn(CheckDMA());
+ PicoVideoFIFOSync(CYCLES_M68K_LINE);
+
+ // need rather tight Z80 sync for emulation of main bus cycle stealing
+ if (Pico.m.scanline&1)
+ if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80))
+ PicoSyncZ80(Pico.t.m68c_aim);
}
-static void do_timing_hacks_vb(void)
+static void do_timing_hacks_start(struct PicoVideo *pv)
{
- if (Pico.m.dma_xfers)
- SekCyclesBurn(CheckDMA());
+ int cycles = PicoVideoFIFOHint();
+
+ SekCyclesBurn(cycles); // prolong cpu HOLD if necessary
+ // XXX how to handle Z80 bus cycle stealing during DMA correctly?
+ if ((Pico.t.z80_buscycles -= cycles<<4) < 0)
+ Pico.t.z80_buscycles = 0;
+ Pico.t.m68c_aim += Pico.m.scanline&1; // add 1 every 2 lines for 488.5 cycles
}
static int PicoFrameHints(void)
{
struct PicoVideo *pv = &Pico.video;
- int line_sample = Pico.m.pal ? 68 : 93;
- int vdp_slots = (Pico.video.reg[12] & 1) ? 18 : 16;
int lines, y, lines_vis, skip;
- int vcnt_wrap, vcnt_adj;
- unsigned int cycles;
int hint; // Hint counter
pevt_log_m68k_o(EVT_FRAME_START);
- if ((PicoIn.opt&POPT_ALT_RENDERER) && !PicoIn.skipFrame && (pv->reg[1]&0x40)) { // fast rend., display enabled
- // draw a frame just after vblank in alternative render mode
- // yes, this will cause 1 frame lag, but this is inaccurate mode anyway.
- PicoFrameFull();
-#ifdef DRAW_FINISH_FUNC
- DRAW_FINISH_FUNC();
-#endif
- skip = 1;
- }
- else skip=PicoIn.skipFrame;
+ skip = PicoIn.skipFrame;
Pico.t.m68c_frame_start = Pico.t.m68c_aim;
- pv->v_counter = Pico.m.scanline = 0;
- z80_resetCycles();
PsndStartFrame();
- // Load H-Int counter
- hint = (pv->status & PVS_ACTIVE) ? pv->hint_cnt : pv->reg[10];
+ hint = pv->hint_cnt;
+ // === active display ===
pv->status |= PVS_ACTIVE;
- for (y = 0; ; y++)
+ for (y = 0; y < 240; y++)
{
- pv->v_counter = Pico.m.scanline = y;
- if ((pv->reg[12]&6) == 6) { // interlace mode 2
- pv->v_counter <<= 1;
- pv->v_counter |= pv->v_counter >> 8;
- pv->v_counter &= 0xff;
- }
-
- if ((y == 224 && !(pv->reg[1] & 8)) || y == 240)
+ if (y == 224 && !(pv->reg[1] & 8))
break;
+ Pico.m.scanline = y;
+ pv->v_counter = PicoVideoGetV(y, 0);
+
PAD_DELAY();
// H-Interrupts:
}
// decide if we draw this line
- if (!skip && (PicoIn.opt & POPT_ALT_RENDERER))
+ if (unlikely(PicoIn.opt & POPT_ALT_RENDERER) && !skip)
{
// find the right moment for frame renderer, when display is no longer blanked
if ((pv->reg[1]&0x40) || y > 100) {
- PicoFrameFull();
+ if (Pico.est.rendstatus & PDRAW_SYNC_NEEDED)
+ PicoFrameFull();
#ifdef DRAW_FINISH_FUNC
DRAW_FINISH_FUNC();
#endif
+ Pico.est.rendstatus &= ~PDRAW_SYNC_NEEDED;
skip = 1;
}
}
- // get samples from sound chips
- if ((y == 224 || y == line_sample) && PsndOut)
- {
- cycles = SekCyclesDone();
-
- if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80))
- PicoSyncZ80(cycles);
-#ifdef PICO_CD
- if (PicoIn.AHW & PAHW_MCD)
- pcd_sync_s68k(cycles, 0);
-#endif
-#ifdef PICO_32X
- p32x_sync_sh2s(cycles);
-#endif
- PsndGetSamples(y);
- }
-
// Run scanline:
Pico.t.m68c_line_start = Pico.t.m68c_aim;
- do_timing_hacks_as(pv, vdp_slots);
+ do_timing_hacks_start(pv);
CPUS_RUN(CYCLES_M68K_LINE);
+ do_timing_hacks_end(pv);
if (PicoLineHook) PicoLineHook();
pevt_log_m68k_o(EVT_NEXT_LINE);
}
- lines_vis = (pv->reg[1] & 8) ? 240 : 224;
- if (y == lines_vis)
- pv->status &= ~PVS_ACTIVE;
+ SyncCPUs(Pico.t.m68c_aim);
if (!skip)
{
if (Pico.est.DrawScanline < y)
- PicoDrawSync(y - 1, 0);
+ PicoVideoSync(-1);
#ifdef DRAW_FINISH_FUNC
DRAW_FINISH_FUNC();
#endif
+ Pico.est.rendstatus &= ~PDRAW_SYNC_NEEDED;
}
+#ifdef PICO_32X
+ p32x_render_frame();
+#endif
- // VDP FIFO
- pv->lwrite_cnt = 0;
- Pico.video.status |= SR_EMPT;
+ // === VBLANK, 1st line ===
+ lines_vis = (pv->reg[1] & 8) ? 240 : 224;
+ if (y == lines_vis)
+ pv->status &= ~PVS_ACTIVE;
+ Pico.m.scanline = y;
+ pv->v_counter = PicoVideoGetV(y, 0);
memcpy(PicoIn.padInt, PicoIn.pad, sizeof(PicoIn.padInt));
PAD_DELAY();
}
pv->status |= SR_VB | PVS_VB2; // go into vblank
+#ifdef PICO_32X
+ p32x_start_blank();
+#endif
// the following SekRun is there for several reasons:
// there must be a delay after vblank bit is set and irq is asserted (Mazin Saga)
// also delay between F bit (bit 7) is set in SR and IRQ happens (Ex-Mutants)
// also delay between last H-int and V-int (Golden Axe 3)
Pico.t.m68c_line_start = Pico.t.m68c_aim;
- do_timing_hacks_vb();
+ PicoVideoFIFOMode(pv->reg[1]&0x40, pv->reg[12]&1);
+ do_timing_hacks_start(pv);
CPUS_RUN(CYCLES_M68K_VINT_LAG);
+ SyncCPUs(Pico.t.m68c_aim);
+
+ // slot 0x00
pv->status |= SR_F;
pv->pending_ints |= 0x20;
+
if (pv->reg[1] & 0x20) {
- Pico.t.m68c_aim = Pico.t.m68c_cnt + 11; // HACK
- SekSyncM68k();
+ // as per https://gendev.spritesmind.net/forum/viewtopic.php?t=2202, IRQ
+ // is usually sampled after operand reading, so the next instruction will
+ // be executed before the IRQ is taken.
+ if (Pico.t.m68c_cnt - Pico.t.m68c_aim < 40) // CPU blocked?
+ SekExecM68k(4);
elprintf(EL_INTS, "vint: @ %06x [%u]", SekPc, SekCyclesDone());
+ // TODO: IRQ usually sampled after operand reading, so insn can't turn it
+ // off? single exception is MOVE.L which samples IRQ after the 1st write?
SekInterrupt(6);
}
- cycles = SekCyclesDone();
- if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80)) {
- PicoSyncZ80(cycles);
+ // slot 0x01
+ if (pv->reg[12] & 2)
+ pv->status ^= SR_ODD; // change odd bit in interlace modes
+ else
+ pv->status &= ~SR_ODD; // never set in non-interlace modes
+
+ // assert Z80 interrupt for one scanline even in busrq hold (Teddy Blues)
+ if (/*Pico.m.z80Run &&*/ !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80)) {
elprintf(EL_INTS, "zint");
- z80_int();
+ z80_int_assert(1);
}
-#ifdef PICO_CD
- if (PicoIn.AHW & PAHW_MCD)
- pcd_sync_s68k(cycles, 0);
-#endif
-#ifdef PICO_32X
- p32x_sync_sh2s(cycles);
- p32x_start_blank();
-#endif
-
- // get samples from sound chips
- if (y == 224 && PsndOut)
- PsndGetSamples(y);
-
// Run scanline:
CPUS_RUN(CYCLES_M68K_LINE - CYCLES_M68K_VINT_LAG);
+ do_timing_hacks_end(pv);
if (PicoLineHook) PicoLineHook();
pevt_log_m68k_o(EVT_NEXT_LINE);
- if (Pico.m.pal) {
- lines = 313;
- vcnt_wrap = 0x103;
- vcnt_adj = 57;
- }
- else {
- lines = 262;
- vcnt_wrap = 0xEB;
- vcnt_adj = 6;
- }
+ if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80))
+ PicoSyncZ80(Pico.t.m68c_aim);
+ z80_int_assert(0);
+ // === VBLANK ===
+ lines = Pico.m.pal ? 313 : 262;
for (y++; y < lines - 1; y++)
{
- pv->v_counter = Pico.m.scanline = y;
- if (y >= vcnt_wrap)
- pv->v_counter -= vcnt_adj;
- if ((pv->reg[12]&6) == 6)
- pv->v_counter = (pv->v_counter << 1) | 1;
- pv->v_counter &= 0xff;
+ Pico.m.scanline = y;
+ pv->v_counter = PicoVideoGetV(y, 1);
PAD_DELAY();
- if ((pv->status & PVS_ACTIVE) && --hint < 0)
+ if (unlikely(pv->status & PVS_ACTIVE) && --hint < 0)
{
hint = pv->reg[10]; // Reload H-Int counter
do_hint(pv);
// Run scanline:
Pico.t.m68c_line_start = Pico.t.m68c_aim;
- do_timing_hacks_vb();
+ do_timing_hacks_start(pv);
CPUS_RUN(CYCLES_M68K_LINE);
+ do_timing_hacks_end(pv);
if (PicoLineHook) PicoLineHook();
pevt_log_m68k_o(EVT_NEXT_LINE);
}
+ if (unlikely(PicoIn.overclockM68k)) {
+ unsigned int l = PicoIn.overclockM68k * lines / 100;
+ while (l-- > 0) {
+ Pico.t.m68c_cnt -= CYCLES_M68K_LINE;
+ do_timing_hacks_start(pv);
+ SekSyncM68k(0);
+ do_timing_hacks_end(pv);
+ }
+ }
+
+ // === VBLANK last line ===
pv->status &= ~(SR_VB | PVS_VB2);
pv->status |= ((pv->reg[1] >> 3) ^ SR_VB) & SR_VB; // forced blanking
// last scanline
- Pico.m.scanline = y;
+ Pico.m.scanline = y++;
pv->v_counter = 0xff;
- pv->lwrite_cnt = 0;
PAD_DELAY();
- if ((pv->status & PVS_ACTIVE) && --hint < 0)
- {
- hint = pv->reg[10]; // Reload H-Int counter
- do_hint(pv);
+ if (unlikely(pv->status & PVS_ACTIVE)) {
+ if (--hint < 0) {
+ hint = pv->reg[10]; // Reload H-Int counter
+ do_hint(pv);
+ }
}
+ else
+ hint = pv->reg[10];
// Run scanline:
Pico.t.m68c_line_start = Pico.t.m68c_aim;
- do_timing_hacks_as(pv, vdp_slots);
+ PicoVideoFIFOMode(pv->reg[1]&0x40, pv->reg[12]&1);
+ do_timing_hacks_start(pv);
CPUS_RUN(CYCLES_M68K_LINE);
+ do_timing_hacks_end(pv);
if (PicoLineHook) PicoLineHook();
pevt_log_m68k_o(EVT_NEXT_LINE);
- // sync cpus
- cycles = SekCyclesDone();
- if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoIn.opt&POPT_EN_Z80))
- PicoSyncZ80(cycles);
- if (PsndOut && ym2612.dacen && PsndDacLine < lines)
- PsndDoDAC(lines - 1);
- if (PsndOut && PsndPsgLine < lines)
- PsndDoPSG(lines - 1);
-
-#ifdef PICO_CD
- if (PicoIn.AHW & PAHW_MCD)
- pcd_sync_s68k(cycles, 0);
-#endif
+ SyncCPUs(Pico.t.m68c_aim);
#ifdef PICO_32X
- p32x_sync_sh2s(cycles);
+ p32x_end_blank();
#endif
- timers_cycle();
+
+ // get samples from sound chips
+ PsndGetSamples(y);
+
+ timers_cycle(cycles_68k_to_z80(Pico.t.m68c_aim - Pico.t.m68c_frame_start));
+ z80_resetCycles();
pv->hint_cnt = hint;
notaz.gp2x.de / picodrive.git / blobdiff