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core, revisit ym2612 busy flag implementation

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kub 2024-06-22 23:12:31 +02:00
parent e948a120ed
commit f5c022a8e4
5 changed files with 24 additions and 16 deletions
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13
pico/memory.c
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@ -1174,7 +1174,7 @@ static int ym2612_write_local(u32 a, u32 d, int is_from_z80)
// 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
Pico.t.ym2612_busy = (cycles << 8) + YMBUSY_ZCYCLES; // Q8 for convenience
switch (addr)
{
@ -1284,9 +1284,11 @@ static u32 ym2612_read_local_68k(void)
void ym2612_pack_state(void)
{
// timers are saved as tick counts, in 16.16 int format
int tac, tat = 0, tbc, tbt = 0;
int tac, tat = 0, tbc, tbt = 0, busy = 0;
tac = 1024 - ym2612.OPN.ST.TA;
tbc = 256 - ym2612.OPN.ST.TB;
if (Pico.t.ym2612_busy > 0)
busy = cycles_z80_to_68k(Pico.t.ym2612_busy);
if (Pico.t.timer_a_next_oflow != TIMER_NO_OFLOW)
tat = (int)((double)(Pico.t.timer_a_step - Pico.t.timer_a_next_oflow)
/ (double)Pico.t.timer_a_step * tac * 65536);
@ -1301,12 +1303,12 @@ void ym2612_pack_state(void)
YM2612PicoStateSave2_940(tat, tbt);
else
#endif
YM2612PicoStateSave2(tat, tbt);
YM2612PicoStateSave2(tat, tbt, busy);
}
void ym2612_unpack_state(void)
{
int i, ret, tac, tat, tbc, tbt;
int i, ret, tac, tat, tbc, tbt, busy = 0;
YM2612PicoStateLoad();
// feed all the registers and update internal state
@ -1336,12 +1338,13 @@ void ym2612_unpack_state(void)
ret = YM2612PicoStateLoad2_940(&tat, &tbt);
else
#endif
ret = YM2612PicoStateLoad2(&tat, &tbt);
ret = YM2612PicoStateLoad2(&tat, &tbt, &busy);
if (ret != 0) {
elprintf(EL_STATUS, "old ym2612 state");
return; // no saved timers
}
Pico.t.ym2612_busy = cycles_68k_to_z80(busy);
tac = (1024 - ym2612.OPN.ST.TA) << 16;
tbc = (256 - ym2612.OPN.ST.TB) << 16;
if (ym2612.OPN.ST.mode & 1)

11
pico/pico_int.h
View file

@ -209,6 +209,7 @@ extern struct DrZ80 drZ80;
// 68k clock = OSC/7, z80 clock = OSC/15, 68k:z80 ratio = 7/15 = 3822.9/8192
#define cycles_68k_to_z80(x) ((x) * 3823 >> 13)
#define cycles_z80_to_68k(x) ((x) * 8777 >> 12)
// ----------------------- SH2 CPU -----------------------
@ -898,10 +899,12 @@ void ym2612_unpack_state(void);
#define TIMER_NO_OFLOW 0x70000000
// tA = 72 * (1024 - TA) / M, with M = mclock/2
#define TIMER_A_TICK_ZCYCLES cycles_68k_to_z80(256LL* 72*2) // Q8
// tB = 16*72 * ( 256 - TB) / M
#define TIMER_B_TICK_ZCYCLES cycles_68k_to_z80(256LL*16*72*2) // Q8
// tA = 24*3 * (1024 - TA) / M, with M = mclock/2
#define TIMER_A_TICK_ZCYCLES cycles_68k_to_z80(256LL* 24*3*2) // Q8
// tB = 16*24*3 * ( 256 - TB) / M
#define TIMER_B_TICK_ZCYCLES cycles_68k_to_z80(256LL*16*24*3*2) // Q8
// busy = 32*3 / M
#define YMBUSY_ZCYCLES cycles_68k_to_z80(256LL* 32*3*2) // Q8
#define timers_cycle(ticks) \
if (Pico.t.ym2612_busy > 0) \

8
pico/sound/ym2612.c
View file

@ -2049,7 +2049,7 @@ typedef struct
UINT32 eg_timer;
UINT32 lfo_cnt;
UINT16 lfo_ampm;
UINT16 unused2;
INT16 busy_timer;
UINT32 keyon_field; // 20
UINT32 kcode_fc_sl3_3;
UINT32 reserved[2];
@ -2063,7 +2063,7 @@ typedef struct
} ym_save_addon2;
void YM2612PicoStateSave2(int tat, int tbt)
void YM2612PicoStateSave2(int tat, int tbt, int busy)
{
ym_save_addon_slot ss;
ym_save_addon2 sa2;
@ -2121,10 +2121,11 @@ void YM2612PicoStateSave2(int tat, int tbt)
sa.eg_timer = ym2612.OPN.eg_timer;
sa.lfo_cnt = ym2612.OPN.lfo_cnt;
sa.lfo_ampm = g_lfo_ampm;
sa.busy_timer = busy;
memcpy(ptr, &sa, sizeof(sa)); // 0x30 max
}
int YM2612PicoStateLoad2(int *tat, int *tbt)
int YM2612PicoStateLoad2(int *tat, int *tbt, int *busy)
{
ym_save_addon_slot ss;
ym_save_addon2 sa2;
@ -2150,6 +2151,7 @@ int YM2612PicoStateLoad2(int *tat, int *tbt)
g_lfo_ampm = sa.lfo_ampm;
if (tat != NULL) *tat = sa.TAT;
if (tbt != NULL) *tbt = sa.TBT;
if (busy != NULL) *busy = sa.busy_timer;
// chans 1,2,3
ptr = &ym2612.REGS[0x0b8];

4
pico/sound/ym2612.h
View file

@ -177,8 +177,8 @@ int YM2612PicoTick_(int n);
void YM2612PicoStateLoad_(void);
void *YM2612GetRegs(void);
void YM2612PicoStateSave2(int tat, int tbt);
int YM2612PicoStateLoad2(int *tat, int *tbt);
void YM2612PicoStateSave2(int tat, int tbt, int busy);
int YM2612PicoStateLoad2(int *tat, int *tbt, int *busy);
/* NB must be macros for compiling GP2X 940 code */
#ifndef __GP2X__