2 * Emulation routines for the RF5C164 PCM chip
3 * (C) notaz, 2007, 2013
5 * This work is licensed under the terms of MAME license.
6 * See COPYING file in the top-level directory.
10 #include "../pico_int.h"
12 #define PCM_STEP_SHIFT 11
14 void pcd_pcm_write(unsigned int a, unsigned int d)
16 unsigned int cycles = SekCyclesDoneS68k();
17 if ((int)(cycles - Pico_mcd->pcm.update_cycles) >= 384)
22 Pico_mcd->pcm.ch[Pico_mcd->pcm.cur_ch].regs[a] = d;
24 else if (a == 7) // control register
27 Pico_mcd->pcm.cur_ch = d & 7;
29 Pico_mcd->pcm.bank = d & 0xf;
30 Pico_mcd->pcm.control = d;
31 elprintf(EL_CD, "pcm control %02x", Pico_mcd->pcm.control);
33 else if (a == 8 && Pico_mcd->pcm.enabled != (u_char)~d)
36 int was_enabled = Pico_mcd->pcm.enabled;
39 for (i = 0; i < 8; i++)
40 if (!(was_enabled & (1 << i)))
41 Pico_mcd->pcm.ch[i].addr =
42 Pico_mcd->pcm.ch[i].regs[6] << (PCM_STEP_SHIFT + 8);
44 Pico_mcd->pcm.enabled = ~d;
48 unsigned int pcd_pcm_read(unsigned int a)
50 unsigned int d, cycles = SekCyclesDoneS68k();
51 if ((int)(cycles - Pico_mcd->pcm.update_cycles) >= 384)
54 d = Pico_mcd->pcm.ch[(a >> 1) & 7].addr >> PCM_STEP_SHIFT;
61 void pcd_pcm_sync(unsigned int to)
63 unsigned int cycles = Pico_mcd->pcm.update_cycles;
64 int mul_l, mul_r, inc, smp;
70 if ((int)(to - cycles) < 384)
73 steps = (to - cycles) / 384;
75 // PCM disabled or all channels off
76 if (!(Pico_mcd->pcm.control & 0x80) || !Pico_mcd->pcm.enabled)
79 out = Pico_mcd->pcm_mixbuf + Pico_mcd->pcm_mixpos * 2;
80 Pico_mcd->pcm_mixbuf_dirty = 1;
81 if (Pico_mcd->pcm_mixpos + steps > PCM_MIXBUF_LEN)
83 steps = PCM_MIXBUF_LEN - Pico_mcd->pcm_mixpos;
85 for (c = 0; c < 8; c++)
87 if (!(Pico_mcd->pcm.enabled & (1 << c)))
88 continue; // channel disabled
90 ch = &Pico_mcd->pcm.ch[c];
92 inc = *(unsigned short *)&ch->regs[2];
93 mul_l = ((int)ch->regs[0] * (ch->regs[1] & 0xf)) >> (5+1);
94 mul_r = ((int)ch->regs[0] * (ch->regs[1] >> 4)) >> (5+1);
96 for (s = 0; s < steps; s++, addr = (addr + inc) & 0x7FFFFFF)
98 smp = Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT];
100 // test for loop signal
103 addr = *(unsigned short *)&ch->regs[4]; // loop_addr
104 smp = Pico_mcd->pcm_ram[addr];
105 addr <<= PCM_STEP_SHIFT;
113 out[s*2 ] += smp * mul_l; // max 128 * 119 = 15232
114 out[s*2+1] += smp * mul_r;
120 Pico_mcd->pcm.update_cycles = cycles + steps * 384;
121 Pico_mcd->pcm_mixpos += steps;
124 void pcd_pcm_update(int *buf32, int length, int stereo)
129 pcd_pcm_sync(SekCyclesDoneS68k());
131 if (!Pico_mcd->pcm_mixbuf_dirty || !(PicoOpt & POPT_EN_MCD_PCM))
134 step = (Pico_mcd->pcm_mixpos << 16) / length;
135 pcm = Pico_mcd->pcm_mixbuf;
138 while (length-- > 0) {
143 pcm += (p >> 16) * 2;
148 while (length-- > 0) {
153 pcm += (p >> 16) * 2;
158 memset(Pico_mcd->pcm_mixbuf, 0,
159 Pico_mcd->pcm_mixpos * 2 * sizeof(Pico_mcd->pcm_mixbuf[0]));
162 Pico_mcd->pcm_mixbuf_dirty = 0;
163 Pico_mcd->pcm_mixpos = 0;
166 // vim:shiftwidth=2:ts=2:expandtab