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core, implement ym2612 busy flag

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kub 2024-03-03 22:57:58 +01:00
parent c066c40ba9
commit 83025d7abe
2 changed files with 12 additions and 5 deletions
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13
pico/memory.c
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@ -1066,6 +1066,8 @@ static int get_scanline(int is_from_z80)
}
#define ym2612_update_status(xcycles) \
ym2612.OPN.ST.status &= ~0x80; \
ym2612.OPN.ST.status |= (xcycles < Pico.t.ym2612_busy) * 0x80; \
if (xcycles >= Pico.t.timer_a_next_oflow) \
ym2612.OPN.ST.status |= (ym2612.OPN.ST.mode >> 2) & 1; \
if (xcycles >= Pico.t.timer_b_next_oflow) \
@ -1131,6 +1133,7 @@ void ym2612_sync_timers(int z80_cycles, int mode_old, int mode_new)
// ym2612 DAC and timer I/O handlers for z80
static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
{
int cycles = is_from_z80 ? z80_cyclesDone() : z80_cycles_from_68k();
int addr;
a &= 3;
@ -1150,6 +1153,10 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
addr = ym2612.OPN.ST.address | ((int)ym2612.addr_A1 << 8);
ym2612.REGS[addr] = d;
// the busy flag in the YM2612 status is actually a 32 cycle timer
// (89.6 Z80 cycles), triggered by any write to the data port.
Pico.t.ym2612_busy = (cycles + 90) << 8; // Q8 for convenience
switch (addr)
{
case 0x24: // timer A High 8
@ -1158,7 +1165,6 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
: ((ym2612.OPN.ST.TA & 0x3fc)|(d&3));
if (ym2612.OPN.ST.TA != TAnew)
{
int cycles = is_from_z80 ? z80_cyclesDone() : z80_cycles_from_68k();
ym2612_sync_timers(cycles, ym2612.OPN.ST.mode, ym2612.OPN.ST.mode);
//elprintf(EL_STATUS, "timer a set %i", TAnew);
ym2612.OPN.ST.TA = TAnew;
@ -1171,7 +1177,6 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
}
case 0x26: // timer B
if (ym2612.OPN.ST.TB != d) {
int cycles = is_from_z80 ? z80_cyclesDone() : z80_cycles_from_68k();
ym2612_sync_timers(cycles, ym2612.OPN.ST.mode, ym2612.OPN.ST.mode);
//elprintf(EL_STATUS, "timer b set %i", d);
ym2612.OPN.ST.TB = d;
@ -1183,7 +1188,6 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
return 0;
case 0x27: { /* mode, timer control */
int old_mode = ym2612.OPN.ST.mode;
int cycles = is_from_z80 ? z80_cyclesDone() : z80_cycles_from_68k();
elprintf(EL_YMTIMER, "st mode %02x", d);
ym2612_sync_timers(cycles, old_mode, d);
@ -1208,7 +1212,6 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
return 0;
}
case 0x2a: { /* DAC data */
int cycles = is_from_z80 ? z80_cyclesDone() : z80_cycles_from_68k();
//elprintf(EL_STATUS, "%03i dac w %08x z80 %i", cycles, d, is_from_z80);
if (ym2612.dacen)
PsndDoDAC(cycles);
@ -1230,7 +1233,7 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
if (PicoIn.opt & POPT_EXT_FM)
return YM2612Write_940(a, d, get_scanline(is_from_z80));
#endif
PsndDoFM(is_from_z80 ? z80_cyclesDone() : z80_cycles_from_68k());
PsndDoFM(cycles);
return YM2612Write_(a, d);
}