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));
51 // cold reset state (tested)
52 Pico_mcd->m.state_flags = PCD_ST_S68K_RST;
53 Pico_mcd->m.busreq = 2; // busreq on, s68k in reset
54 Pico_mcd->s68k_regs[3] = 1; // 2M word RAM mode, m68k access
55 memset(Pico_mcd->bios + 0x70, 0xff, 4);
58 void pcd_soft_reset(void)
60 // Reset_CD(); // breaks Fahrenheit CD swap
63 #ifdef _ASM_CD_MEMORY_C
64 //PicoMemResetCDdecode(1); // don't have to call this in 2M mode
67 pcd_event_schedule_s68k(PCD_EVENT_CDC, 12500000/75);
69 // TODO: test if register state/timers change
72 PICO_INTERNAL int PicoResetMCD(void)
74 // reset button doesn't affect MCD hardware
76 // use SRam.data for RAM cart
77 if (PicoOpt & POPT_EN_MCD_RAMCART) {
78 if (SRam.data == NULL)
79 SRam.data = calloc(1, 0x12000);
81 else if (SRam.data != NULL) {
85 SRam.start = SRam.end = 0; // unused
90 static __inline void SekRunS68k(unsigned int to)
95 if ((cyc_do = SekCycleAimS68k - SekCycleCntS68k) <= 0)
98 if (SekShouldInterrupt())
99 Pico_mcd->m.s68k_poll_a = 0;
101 SekCycleCntS68k += cyc_do;
102 #if defined(EMU_C68K)
103 PicoCpuCS68k.cycles = cyc_do;
104 CycloneRun(&PicoCpuCS68k);
105 SekCycleCntS68k -= PicoCpuCS68k.cycles;
106 #elif defined(EMU_M68K)
107 m68k_set_context(&PicoCpuMS68k);
108 SekCycleCntS68k += m68k_execute(cyc_do) - cyc_do;
109 m68k_set_context(&PicoCpuMM68k);
110 #elif defined(EMU_F68K)
111 g_m68kcontext = &PicoCpuFS68k;
112 SekCycleCntS68k += fm68k_emulate(cyc_do, 0) - cyc_do;
113 g_m68kcontext = &PicoCpuFM68k;
117 static void pcd_set_cycle_mult(void)
119 // ~1.63 for NTSC, ~1.645 for PAL
121 mcd_m68k_cycle_mult = ((12500000ull << 16) / (50*312*488));
123 mcd_m68k_cycle_mult = ((12500000ull << 16) / (60*262*488)) + 1;
126 unsigned int pcd_cycles_m68k_to_s68k(unsigned int c)
128 return (long long)c * mcd_m68k_cycle_mult >> 16;
132 static void pcd_cdc_event(unsigned int now)
136 pcd_event_schedule(now, PCD_EVENT_CDC, 12500000/75);
139 static void pcd_int3_timer_event(unsigned int now)
141 if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN3) {
142 elprintf(EL_INTS|EL_CD, "s68k: timer irq 3");
146 if (Pico_mcd->s68k_regs[0x31] != 0)
147 pcd_event_schedule(now, PCD_EVENT_TIMER3,
148 Pico_mcd->s68k_regs[0x31] * 384);
151 static void pcd_dma_event(unsigned int now)
153 int ddx = Pico_mcd->s68k_regs[4] & 7;
154 Update_CDC_TRansfer(ddx);
157 typedef void (event_cb)(unsigned int now);
159 /* times are in s68k (12.5MHz) cycles */
160 unsigned int pcd_event_times[PCD_EVENT_COUNT];
161 static unsigned int event_time_next;
162 static event_cb *pcd_event_cbs[PCD_EVENT_COUNT] = {
163 [PCD_EVENT_CDC] = pcd_cdc_event,
164 [PCD_EVENT_TIMER3] = pcd_int3_timer_event,
165 [PCD_EVENT_GFX] = gfx_update,
166 [PCD_EVENT_DMA] = pcd_dma_event,
169 void pcd_event_schedule(unsigned int now, enum pcd_event event, int after)
176 pcd_event_times[event] = 0;
182 elprintf(EL_CD, "cd: new event #%u %u->%u", event, now, when);
183 pcd_event_times[event] = when;
185 if (event_time_next == 0 || CYCLES_GT(event_time_next, when))
186 event_time_next = when;
189 void pcd_event_schedule_s68k(enum pcd_event event, int after)
191 if (SekCyclesLeftS68k > after)
192 SekEndRunS68k(after);
194 pcd_event_schedule(SekCyclesDoneS68k(), event, after);
197 static void pcd_run_events(unsigned int until)
199 int oldest, oldest_diff, time;
203 oldest = -1, oldest_diff = 0x7fffffff;
205 for (i = 0; i < PCD_EVENT_COUNT; i++) {
206 if (pcd_event_times[i]) {
207 diff = pcd_event_times[i] - until;
208 if (diff < oldest_diff) {
215 if (oldest_diff <= 0) {
216 time = pcd_event_times[oldest];
217 pcd_event_times[oldest] = 0;
218 elprintf(EL_CD, "cd: run event #%d %u", oldest, time);
219 pcd_event_cbs[oldest](time);
221 else if (oldest_diff < 0x7fffffff) {
222 event_time_next = pcd_event_times[oldest];
232 elprintf(EL_CD, "cd: next event #%d at %u",
233 oldest, event_time_next);
236 int pcd_sync_s68k(unsigned int m68k_target, int m68k_poll_sync)
238 #define now SekCycleCntS68k
239 unsigned int s68k_target;
242 target = m68k_target - mcd_m68k_cycle_base;
243 s68k_target = mcd_s68k_cycle_base +
244 ((unsigned long long)target * mcd_m68k_cycle_mult >> 16);
246 elprintf(EL_CD, "s68k sync to %u, %u->%u",
247 m68k_target, now, s68k_target);
249 if (Pico_mcd->m.busreq != 1) { /* busreq/reset */
250 SekCycleCntS68k = SekCycleAimS68k = s68k_target;
251 pcd_run_events(m68k_target);
255 while (CYCLES_GT(s68k_target, now)) {
256 if (event_time_next && CYCLES_GE(now, event_time_next))
259 target = s68k_target;
260 if (event_time_next && CYCLES_GT(target, event_time_next))
261 target = event_time_next;
264 if (m68k_poll_sync && Pico_mcd->m.m68k_poll_cnt == 0)
268 return s68k_target - now;
272 #define pcd_run_cpus_normal pcd_run_cpus
273 //#define pcd_run_cpus_lockstep pcd_run_cpus
275 static void SekSyncM68k(void);
277 void pcd_run_cpus_normal(int m68k_cycles)
279 SekCycleAim += m68k_cycles;
280 if (SekShouldInterrupt() || Pico_mcd->m.m68k_poll_cnt < 12)
281 Pico_mcd->m.m68k_poll_cnt = 0;
282 else if (Pico_mcd->m.m68k_poll_cnt >= 16) {
283 int s68k_left = pcd_sync_s68k(SekCycleAim, 1);
284 if (s68k_left <= 0) {
285 elprintf(EL_CDPOLL, "m68k poll [%02x] x%d @%06x",
286 Pico_mcd->m.m68k_poll_a, Pico_mcd->m.m68k_poll_cnt, SekPc);
287 SekCycleCnt = SekCycleAim;
290 SekCycleCnt = SekCycleAim - (s68k_left * 40220 >> 16);
296 void pcd_run_cpus_lockstep(int m68k_cycles)
298 unsigned int target = SekCycleAim + m68k_cycles;
302 pcd_sync_s68k(SekCycleAim, 0);
303 } while (CYCLES_GT(target, SekCycleAim));
305 SekCycleAim = target;
309 #define CPUS_RUN(m68k_cycles) \
310 pcd_run_cpus(m68k_cycles)
312 #include "../pico_cmn.c"
315 void pcd_prepare_frame(void)
317 pcd_set_cycle_mult();
319 // need this because we can't have direct mapping between
320 // master<->slave cycle counters because of overflows
321 mcd_m68k_cycle_base = SekCycleAim;
322 mcd_s68k_cycle_base = SekCycleAimS68k;
325 PICO_INTERNAL void PicoFrameMCD(void)
333 void pcd_state_loaded(void)
338 pcd_set_cycle_mult();
339 pcd_state_loaded_mem();
341 memset(Pico_mcd->pcm_mixbuf, 0, sizeof(Pico_mcd->pcm_mixbuf));
342 Pico_mcd->pcm_mixbuf_dirty = 0;
343 Pico_mcd->pcm_mixpos = 0;
344 Pico_mcd->pcm_regs_dirty = 1;
347 cycles = pcd_cycles_m68k_to_s68k(SekCycleAim);
348 diff = cycles - SekCycleAimS68k;
349 if (diff < -1000 || diff > 1000) {
350 SekCycleCntS68k = SekCycleAimS68k = cycles;
352 if (pcd_event_times[PCD_EVENT_CDC] == 0) {
353 pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_CDC, 12500000/75);
355 if (Pico_mcd->s68k_regs[0x31])
356 pcd_event_schedule(SekCycleAimS68k, PCD_EVENT_TIMER3,
357 Pico_mcd->s68k_regs[0x31] * 384);
359 if (Pico_mcd->scd.Status_CDC & 0x08)
360 Update_CDC_TRansfer(Pico_mcd->s68k_regs[4] & 7);
363 diff = cycles - Pico_mcd->pcm.update_cycles;
364 if ((unsigned int)diff > 12500000/50)
365 Pico_mcd->pcm.update_cycles = cycles;
369 pcd_run_events(SekCycleCntS68k);
372 // vim:shiftwidth=2:ts=2:expandtab