1 #include "../PicoInt.h"
4 static unsigned int g_rate = 0; // 18.14 fixed point
6 void pcm_write(unsigned int a, unsigned int d)
8 //printf("pcm_write(%i, %02x)\n", a, d);
12 Pico_mcd->pcm.ch[Pico_mcd->pcm.cur_ch].regs[a] = d;
14 else if (a == 7) // control register
16 if (d & 0x40) Pico_mcd->pcm.cur_ch = d & 7;
17 else Pico_mcd->pcm.bank = d & 0xf;
18 Pico_mcd->pcm.control = d;
19 // dprintf("pcm control=%02x", Pico_mcd->pcm.control);
21 else if (a == 8) // sound on/off
23 if (!(Pico_mcd->pcm.enabled & 0x01)) Pico_mcd->pcm.ch[0].addr =
24 Pico_mcd->pcm.ch[0].regs[6] << (PCM_STEP_SHIFT + 8);
25 if (!(Pico_mcd->pcm.enabled & 0x02)) Pico_mcd->pcm.ch[1].addr =
26 Pico_mcd->pcm.ch[1].regs[6] << (PCM_STEP_SHIFT + 8);
27 if (!(Pico_mcd->pcm.enabled & 0x04)) Pico_mcd->pcm.ch[2].addr =
28 Pico_mcd->pcm.ch[2].regs[6] << (PCM_STEP_SHIFT + 8);
29 if (!(Pico_mcd->pcm.enabled & 0x08)) Pico_mcd->pcm.ch[3].addr =
30 Pico_mcd->pcm.ch[3].regs[6] << (PCM_STEP_SHIFT + 8);
31 if (!(Pico_mcd->pcm.enabled & 0x10)) Pico_mcd->pcm.ch[4].addr =
32 Pico_mcd->pcm.ch[4].regs[6] << (PCM_STEP_SHIFT + 8);
33 if (!(Pico_mcd->pcm.enabled & 0x20)) Pico_mcd->pcm.ch[5].addr =
34 Pico_mcd->pcm.ch[5].regs[6] << (PCM_STEP_SHIFT + 8);
35 if (!(Pico_mcd->pcm.enabled & 0x40)) Pico_mcd->pcm.ch[6].addr =
36 Pico_mcd->pcm.ch[6].regs[6] << (PCM_STEP_SHIFT + 8);
37 if (!(Pico_mcd->pcm.enabled & 0x80)) Pico_mcd->pcm.ch[7].addr =
38 Pico_mcd->pcm.ch[7].regs[6] << (PCM_STEP_SHIFT + 8);
39 // printf("addr %x %x %x %x %x %x %x %x\n", Pico_mcd->pcm.ch[0].addr, Pico_mcd->pcm.ch[1].addr
40 // , Pico_mcd->pcm.ch[2].addr, Pico_mcd->pcm.ch[3].addr, Pico_mcd->pcm.ch[4].addr, Pico_mcd->pcm.ch[5].addr
41 // , Pico_mcd->pcm.ch[6].addr, Pico_mcd->pcm.ch[7].addr);
43 Pico_mcd->pcm.enabled = ~d;
44 //printf("enabled=%02x\n", Pico_mcd->pcm.enabled);
49 void pcm_set_rate(int rate)
51 double step = 31.8 * 1024.0 / (double) rate; // max <4 @ 8000Hz
53 g_rate = (unsigned int) step;
54 printf("g_rate: %08x\n", g_rate);
58 // TODO: make use of the fact that max_length == 3
60 void pcm_update(int *buffer, int length, int stereo)
63 unsigned int step, addr;
64 int mul_l, mul_r, smp;
69 // PCM disabled or all channels off (to be checked by caller)
70 //if (!(Pico_mcd->pcm.control & 0x80) || !Pico_mcd->pcm.enabled) return;
72 //printf("-- upd %i\n", length);
74 for (i = 0; i < 8; i++)
76 if (!(Pico_mcd->pcm.enabled & (1 << i))) continue; // channel disabled
79 ch = &Pico_mcd->pcm.ch[i];
81 addr = ch->addr; // >> PCM_STEP_SHIFT;
82 mul_l = ((int)ch->regs[0] * (ch->regs[1] & 0xf)) >> (5+1); // (env * pan) >> 5
83 mul_r = ((int)ch->regs[0] * (ch->regs[1] >> 4)) >> (5+1);
84 step = ((unsigned int)(*(unsigned short *)&ch->regs[2]) * g_rate) >> 14; // freq step
85 // printf("step=%i, cstep=%i, mul_l=%i, mul_r=%i, ch=%i, addr=%x, en=%02x\n",
86 // *(unsigned short *)&ch->regs[2], step, mul_l, mul_r, i, addr, Pico_mcd->pcm.enabled);
88 if (!stereo && mul_l < mul_r) mul_l = mul_r;
90 for (j = 0; j < length; j++)
92 // printf("addr=%08x\n", addr);
93 smp = Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT];
95 // test for loop signal
98 addr = *(unsigned short *)&ch->regs[4]; // loop_addr
99 smp = Pico_mcd->pcm_ram[addr];
100 addr <<= PCM_STEP_SHIFT;
101 if (smp == 0xff) break;
104 if (smp & 0x80) smp = -(smp & 0x7f);
106 *out++ += smp * mul_l; // max 128 * 119 = 15232
108 *out++ += smp * mul_r;
110 // update address register
111 k = (addr >> PCM_STEP_SHIFT) + 1;
112 addr = (addr + step) & 0x7FFFFFF;
114 for(; k < (addr >> PCM_STEP_SHIFT); k++)
116 if (Pico_mcd->pcm_ram[k] == 0xff)
118 addr = (unsigned int)(*(unsigned short *)&ch->regs[4]) << PCM_STEP_SHIFT; // loop_addr
124 if (Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT] == 0xff)
125 addr = (unsigned int)(*(unsigned short *)&ch->regs[4]) << PCM_STEP_SHIFT; // loop_addr