5 * This work is licensed under the terms of MAME license.
6 * See COPYING file in the top-level directory.
9 #include "../pico_int.h"
10 #include "../sound/ym2612.h"
12 extern unsigned char formatted_bram[4*0x10];
14 static unsigned int mcd_m68k_cycle_mult;
15 static unsigned int mcd_m68k_cycle_base;
16 static unsigned int mcd_s68k_cycle_base;
18 void (*PicoMCDopenTray)(void) = NULL;
19 void (*PicoMCDcloseTray)(void) = NULL;
22 PICO_INTERNAL void PicoInitMCD(void)
29 PICO_INTERNAL void PicoExitMCD(void)
34 PICO_INTERNAL void PicoPowerMCD(void)
36 SekCycleCntS68k = SekCycleAimS68k = 0;
38 int fmt_size = sizeof(formatted_bram);
39 memset(Pico_mcd->prg_ram, 0, sizeof(Pico_mcd->prg_ram));
40 memset(Pico_mcd->word_ram2M, 0, sizeof(Pico_mcd->word_ram2M));
41 memset(Pico_mcd->pcm_ram, 0, sizeof(Pico_mcd->pcm_ram));
42 memset(Pico_mcd->bram, 0, sizeof(Pico_mcd->bram));
43 memcpy(Pico_mcd->bram + sizeof(Pico_mcd->bram) - fmt_size,
44 formatted_bram, fmt_size);
45 memset(Pico_mcd->s68k_regs, 0, sizeof(Pico_mcd->s68k_regs));
46 memset(&Pico_mcd->pcm, 0, sizeof(Pico_mcd->pcm));
47 memset(&Pico_mcd->m, 0, sizeof(Pico_mcd->m));
52 // cold reset state (tested)
53 Pico_mcd->m.state_flags = PCD_ST_S68K_RST;
54 Pico_mcd->m.busreq = 2; // busreq on, s68k in reset
55 Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode, m68k access
56 memset(Pico_mcd->bios + 0x70, 0xff, 4);
59 void pcd_soft_reset(void)
61 // Reset_CD(); // breaks Fahrenheit CD swap
63 Pico_mcd->m.s68k_pend_ints = 0;
66 #ifdef _ASM_CD_MEMORY_C
67 //PicoMemResetCDdecode(1); // don't have to call this in 2M mode
70 pcd_event_schedule_s68k(PCD_EVENT_CDC, 12500000/75);
72 // TODO: test if register state/timers change
75 PICO_INTERNAL int PicoResetMCD(void)
77 // reset button doesn't affect MCD hardware
79 // use SRam.data for RAM cart
80 if (PicoOpt & POPT_EN_MCD_RAMCART) {
81 if (SRam.data == NULL)
82 SRam.data = calloc(1, 0x12000);
84 else if (SRam.data != NULL) {
88 SRam.start = SRam.end = 0; // unused
93 static __inline void SekRunS68k(unsigned int to)
98 if ((cyc_do = SekCycleAimS68k - SekCycleCntS68k) <= 0)
101 if (SekShouldInterrupt())
102 Pico_mcd->m.s68k_poll_a = 0;
104 SekCycleCntS68k += cyc_do;
105 #if defined(EMU_C68K)
106 PicoCpuCS68k.cycles = cyc_do;
107 CycloneRun(&PicoCpuCS68k);
108 SekCycleCntS68k -= PicoCpuCS68k.cycles;
109 #elif defined(EMU_M68K)
110 m68k_set_context(&PicoCpuMS68k);
111 SekCycleCntS68k += m68k_execute(cyc_do) - cyc_do;
112 m68k_set_context(&PicoCpuMM68k);
113 #elif defined(EMU_F68K)
114 g_m68kcontext = &PicoCpuFS68k;
115 SekCycleCntS68k += fm68k_emulate(cyc_do, 0) - cyc_do;
116 g_m68kcontext = &PicoCpuFM68k;
120 static void pcd_set_cycle_mult(void)
122 // ~1.63 for NTSC, ~1.645 for PAL
124 mcd_m68k_cycle_mult = ((12500000ull << 16) / (50*312*488));
126 mcd_m68k_cycle_mult = ((12500000ull << 16) / (60*262*488)) + 1;
129 unsigned int pcd_cycles_m68k_to_s68k(unsigned int c)
131 return (long long)c * mcd_m68k_cycle_mult >> 16;
135 static void pcd_cdc_event(unsigned int now)
139 pcd_event_schedule(now, PCD_EVENT_CDC, 12500000/75);
142 static void pcd_int3_timer_event(unsigned int now)
144 if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN3) {
145 elprintf(EL_INTS|EL_CD, "s68k: timer irq 3");
149 if (Pico_mcd->s68k_regs[0x31] != 0)
150 pcd_event_schedule(now, PCD_EVENT_TIMER3,
151 Pico_mcd->s68k_regs[0x31] * 384);
154 static void pcd_dma_event(unsigned int now)
159 typedef void (event_cb)(unsigned int now);
161 /* times are in s68k (12.5MHz) cycles */
162 unsigned int pcd_event_times[PCD_EVENT_COUNT];
163 static unsigned int event_time_next;
164 static event_cb *pcd_event_cbs[PCD_EVENT_COUNT] = {
165 [PCD_EVENT_CDC] = pcd_cdc_event,
166 [PCD_EVENT_TIMER3] = pcd_int3_timer_event,
167 [PCD_EVENT_GFX] = gfx_update,
168 [PCD_EVENT_DMA] = pcd_dma_event,
171 void pcd_event_schedule(unsigned int now, enum pcd_event event, int after)
178 pcd_event_times[event] = 0;
184 elprintf(EL_CD, "cd: new event #%u %u->%u", event, now, when);
185 pcd_event_times[event] = when;
187 if (event_time_next == 0 || CYCLES_GT(event_time_next, when))
188 event_time_next = when;
191 void pcd_event_schedule_s68k(enum pcd_event event, int after)
193 if (SekCyclesLeftS68k > after)
194 SekEndRunS68k(after);
196 pcd_event_schedule(SekCyclesDoneS68k(), event, after);
199 static void pcd_run_events(unsigned int until)
201 int oldest, oldest_diff, time;
205 oldest = -1, oldest_diff = 0x7fffffff;
207 for (i = 0; i < PCD_EVENT_COUNT; i++) {
208 if (pcd_event_times[i]) {
209 diff = pcd_event_times[i] - until;
210 if (diff < oldest_diff) {
217 if (oldest_diff <= 0) {
218 time = pcd_event_times[oldest];
219 pcd_event_times[oldest] = 0;
220 elprintf(EL_CD, "cd: run event #%d %u", oldest, time);
221 pcd_event_cbs[oldest](time);
223 else if (oldest_diff < 0x7fffffff) {
224 event_time_next = pcd_event_times[oldest];
234 elprintf(EL_CD, "cd: next event #%d at %u",
235 oldest, event_time_next);
238 int pcd_sync_s68k(unsigned int m68k_target, int m68k_poll_sync)
240 #define now SekCycleCntS68k
241 unsigned int s68k_target;
244 target = m68k_target - mcd_m68k_cycle_base;
245 s68k_target = mcd_s68k_cycle_base +
246 ((unsigned long long)target * mcd_m68k_cycle_mult >> 16);
248 elprintf(EL_CD, "s68k sync to %u, %u->%u",
249 m68k_target, now, s68k_target);
251 if (Pico_mcd->m.busreq != 1) { /* busreq/reset */
252 SekCycleCntS68k = SekCycleAimS68k = s68k_target;
253 pcd_run_events(m68k_target);
257 while (CYCLES_GT(s68k_target, now)) {
258 if (event_time_next && CYCLES_GE(now, event_time_next))
261 target = s68k_target;
262 if (event_time_next && CYCLES_GT(target, event_time_next))
263 target = event_time_next;
266 if (m68k_poll_sync && Pico_mcd->m.m68k_poll_cnt == 0)
270 return s68k_target - now;
274 #define pcd_run_cpus_normal pcd_run_cpus
275 //#define pcd_run_cpus_lockstep pcd_run_cpus
277 static void SekSyncM68k(void);
279 void pcd_run_cpus_normal(int m68k_cycles)
281 SekCycleAim += m68k_cycles;
282 if (SekShouldInterrupt() || Pico_mcd->m.m68k_poll_cnt < 12)
283 Pico_mcd->m.m68k_poll_cnt = 0;
284 else if (Pico_mcd->m.m68k_poll_cnt >= 16) {
285 int s68k_left = pcd_sync_s68k(SekCycleAim, 1);
286 if (s68k_left <= 0) {
287 elprintf(EL_CDPOLL, "m68k poll [%02x] x%d @%06x",
288 Pico_mcd->m.m68k_poll_a, Pico_mcd->m.m68k_poll_cnt, SekPc);
289 SekCycleCnt = SekCycleAim;
292 SekCycleCnt = SekCycleAim - (s68k_left * 40220 >> 16);
298 void pcd_run_cpus_lockstep(int m68k_cycles)
300 unsigned int target = SekCycleAim + m68k_cycles;
304 pcd_sync_s68k(SekCycleAim, 0);
305 } while (CYCLES_GT(target, SekCycleAim));
307 SekCycleAim = target;
311 #define CPUS_RUN(m68k_cycles) \
312 pcd_run_cpus(m68k_cycles)
314 #include "../pico_cmn.c"
317 void pcd_prepare_frame(void)
319 pcd_set_cycle_mult();
321 // need this because we can't have direct mapping between
322 // master<->slave cycle counters because of overflows
323 mcd_m68k_cycle_base = SekCycleAim;
324 mcd_s68k_cycle_base = SekCycleAimS68k;
327 PICO_INTERNAL void PicoFrameMCD(void)
335 void pcd_state_loaded(void)
340 pcd_set_cycle_mult();
341 pcd_state_loaded_mem();
343 memset(Pico_mcd->pcm_mixbuf, 0, sizeof(Pico_mcd->pcm_mixbuf));
344 Pico_mcd->pcm_mixbuf_dirty = 0;
345 Pico_mcd->pcm_mixpos = 0;
346 Pico_mcd->pcm_regs_dirty = 1;
349 cycles = pcd_cycles_m68k_to_s68k(SekCycleAim);
350 diff = cycles - SekCycleAimS68k;
351 if (diff < -1000 || diff > 1000) {
352 SekCycleCntS68k = SekCycleAimS68k = cycles;
354 if (pcd_event_times[PCD_EVENT_CDC] == 0) {
355 pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_CDC, 12500000/75);
357 if (Pico_mcd->s68k_regs[0x31])
358 pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_TIMER3,
359 Pico_mcd->s68k_regs[0x31] * 384);
362 diff = cycles - Pico_mcd->pcm.update_cycles;
363 if ((unsigned int)diff > 12500000/50)
364 Pico_mcd->pcm.update_cycles = cycles;
368 pcd_run_events(SekCycleCntS68k);
371 // vim:shiftwidth=2:ts=2:expandtab