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1 | // Emulation routines for the RF5C164 PCM chip. |
2 | // Based on Gens code by Stéphane Dallongeville |
3 | // (c) Copyright 2007, Grazvydas "notaz" Ignotas |
4 | |
abe0ea43 |
5 | #include "../PicoInt.h" |
6 | #include "pcm.h" |
7 | |
8 | static unsigned int g_rate = 0; // 18.14 fixed point |
9 | |
10 | void pcm_write(unsigned int a, unsigned int d) |
11 | { |
12 | //printf("pcm_write(%i, %02x)\n", a, d); |
13 | |
14 | if (a < 7) |
15 | { |
16 | Pico_mcd->pcm.ch[Pico_mcd->pcm.cur_ch].regs[a] = d; |
17 | } |
18 | else if (a == 7) // control register |
19 | { |
20 | if (d & 0x40) Pico_mcd->pcm.cur_ch = d & 7; |
21 | else Pico_mcd->pcm.bank = d & 0xf; |
22 | Pico_mcd->pcm.control = d; |
23 | // dprintf("pcm control=%02x", Pico_mcd->pcm.control); |
24 | } |
25 | else if (a == 8) // sound on/off |
26 | { |
27 | if (!(Pico_mcd->pcm.enabled & 0x01)) Pico_mcd->pcm.ch[0].addr = |
28 | Pico_mcd->pcm.ch[0].regs[6] << (PCM_STEP_SHIFT + 8); |
29 | if (!(Pico_mcd->pcm.enabled & 0x02)) Pico_mcd->pcm.ch[1].addr = |
30 | Pico_mcd->pcm.ch[1].regs[6] << (PCM_STEP_SHIFT + 8); |
31 | if (!(Pico_mcd->pcm.enabled & 0x04)) Pico_mcd->pcm.ch[2].addr = |
32 | Pico_mcd->pcm.ch[2].regs[6] << (PCM_STEP_SHIFT + 8); |
33 | if (!(Pico_mcd->pcm.enabled & 0x08)) Pico_mcd->pcm.ch[3].addr = |
34 | Pico_mcd->pcm.ch[3].regs[6] << (PCM_STEP_SHIFT + 8); |
35 | if (!(Pico_mcd->pcm.enabled & 0x10)) Pico_mcd->pcm.ch[4].addr = |
36 | Pico_mcd->pcm.ch[4].regs[6] << (PCM_STEP_SHIFT + 8); |
37 | if (!(Pico_mcd->pcm.enabled & 0x20)) Pico_mcd->pcm.ch[5].addr = |
38 | Pico_mcd->pcm.ch[5].regs[6] << (PCM_STEP_SHIFT + 8); |
39 | if (!(Pico_mcd->pcm.enabled & 0x40)) Pico_mcd->pcm.ch[6].addr = |
40 | Pico_mcd->pcm.ch[6].regs[6] << (PCM_STEP_SHIFT + 8); |
41 | if (!(Pico_mcd->pcm.enabled & 0x80)) Pico_mcd->pcm.ch[7].addr = |
42 | Pico_mcd->pcm.ch[7].regs[6] << (PCM_STEP_SHIFT + 8); |
43 | // printf("addr %x %x %x %x %x %x %x %x\n", Pico_mcd->pcm.ch[0].addr, Pico_mcd->pcm.ch[1].addr |
44 | // , Pico_mcd->pcm.ch[2].addr, Pico_mcd->pcm.ch[3].addr, Pico_mcd->pcm.ch[4].addr, Pico_mcd->pcm.ch[5].addr |
45 | // , Pico_mcd->pcm.ch[6].addr, Pico_mcd->pcm.ch[7].addr); |
46 | |
47 | Pico_mcd->pcm.enabled = ~d; |
48 | //printf("enabled=%02x\n", Pico_mcd->pcm.enabled); |
49 | } |
50 | } |
51 | |
52 | |
53 | void pcm_set_rate(int rate) |
54 | { |
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55 | float step = 31.8 * 1024.0 / (float) rate; // max <4 @ 8000Hz |
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56 | step *= 256*256/4; |
57 | g_rate = (unsigned int) step; |
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58 | if (step - (float) g_rate >= 0.5) g_rate++; |
59 | printf("g_rate: %f %08x\n", (double)step, g_rate); |
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60 | } |
61 | |
62 | |
63 | // TODO: make use of the fact that max_length == 3 |
64 | |
65 | void pcm_update(int *buffer, int length, int stereo) |
66 | { |
67 | struct pcm_chan *ch; |
68 | unsigned int step, addr; |
69 | int mul_l, mul_r, smp; |
70 | int i, j, k; |
71 | int *out; |
72 | |
73 | |
74 | // PCM disabled or all channels off (to be checked by caller) |
75 | //if (!(Pico_mcd->pcm.control & 0x80) || !Pico_mcd->pcm.enabled) return; |
76 | |
77 | //printf("-- upd %i\n", length); |
78 | |
79 | for (i = 0; i < 8; i++) |
80 | { |
81 | if (!(Pico_mcd->pcm.enabled & (1 << i))) continue; // channel disabled |
82 | |
83 | out = buffer; |
84 | ch = &Pico_mcd->pcm.ch[i]; |
85 | |
86 | addr = ch->addr; // >> PCM_STEP_SHIFT; |
87 | mul_l = ((int)ch->regs[0] * (ch->regs[1] & 0xf)) >> (5+1); // (env * pan) >> 5 |
88 | mul_r = ((int)ch->regs[0] * (ch->regs[1] >> 4)) >> (5+1); |
89 | step = ((unsigned int)(*(unsigned short *)&ch->regs[2]) * g_rate) >> 14; // freq step |
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90 | // fprintf(stderr, "step=%i, cstep=%i, mul_l=%i, mul_r=%i, ch=%i, addr=%x, en=%02x\n", |
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91 | // *(unsigned short *)&ch->regs[2], step, mul_l, mul_r, i, addr, Pico_mcd->pcm.enabled); |
92 | |
93 | if (!stereo && mul_l < mul_r) mul_l = mul_r; |
94 | |
95 | for (j = 0; j < length; j++) |
96 | { |
97 | // printf("addr=%08x\n", addr); |
98 | smp = Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT]; |
99 | |
100 | // test for loop signal |
101 | if (smp == 0xff) |
102 | { |
103 | addr = *(unsigned short *)&ch->regs[4]; // loop_addr |
104 | smp = Pico_mcd->pcm_ram[addr]; |
105 | addr <<= PCM_STEP_SHIFT; |
106 | if (smp == 0xff) break; |
107 | } |
108 | |
109 | if (smp & 0x80) smp = -(smp & 0x7f); |
110 | |
111 | *out++ += smp * mul_l; // max 128 * 119 = 15232 |
112 | if(stereo) |
113 | *out++ += smp * mul_r; |
114 | |
115 | // update address register |
116 | k = (addr >> PCM_STEP_SHIFT) + 1; |
117 | addr = (addr + step) & 0x7FFFFFF; |
118 | |
119 | for(; k < (addr >> PCM_STEP_SHIFT); k++) |
120 | { |
121 | if (Pico_mcd->pcm_ram[k] == 0xff) |
122 | { |
123 | addr = (unsigned int)(*(unsigned short *)&ch->regs[4]) << PCM_STEP_SHIFT; // loop_addr |
124 | break; |
125 | } |
126 | } |
127 | } |
128 | |
129 | if (Pico_mcd->pcm_ram[addr >> PCM_STEP_SHIFT] == 0xff) |
130 | addr = (unsigned int)(*(unsigned short *)&ch->regs[4]) << PCM_STEP_SHIFT; // loop_addr |
131 | |
132 | ch->addr = addr; |
133 | } |
134 | } |
135 | |