+// Emulation routines for the RF5C164 PCM chip.
+// Based on Gens code by Stéphane Dallongeville
+// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+
#include "../PicoInt.h"
#include "pcm.h"
static unsigned int g_rate = 0; // 18.14 fixed point
-void pcm_write(unsigned int a, unsigned int d)
+PICO_INTERNAL_ASM void pcm_write(unsigned int a, unsigned int d)
{
//printf("pcm_write(%i, %02x)\n", a, d);
}
-void pcm_set_rate(int rate)
+PICO_INTERNAL void pcm_set_rate(int rate)
{
- double step = 31.8 * 1024.0 / (double) rate; // max <4 @ 8000Hz
+ float step = 31.8 * 1024.0 / (float) rate; // max <4 @ 8000Hz
step *= 256*256/4;
g_rate = (unsigned int) step;
- printf("g_rate: %08x\n", g_rate);
+ if (step - (float) g_rate >= 0.5) g_rate++;
+ elprintf(EL_STATUS, "g_rate: %f %08x\n", (double)step, g_rate);
}
-// TODO: make use of the fact that max_length == 3
-
-void pcm_update(int *buffer, int length, int stereo)
+PICO_INTERNAL void pcm_update(int *buffer, int length, int stereo)
{
struct pcm_chan *ch;
unsigned int step, addr;
mul_l = ((int)ch->regs[0] * (ch->regs[1] & 0xf)) >> (5+1); // (env * pan) >> 5
mul_r = ((int)ch->regs[0] * (ch->regs[1] >> 4)) >> (5+1);
step = ((unsigned int)(*(unsigned short *)&ch->regs[2]) * g_rate) >> 14; // freq step
-// printf("step=%i, cstep=%i, mul_l=%i, mul_r=%i, ch=%i, addr=%x, en=%02x\n",
+// fprintf(stderr, "step=%i, cstep=%i, mul_l=%i, mul_r=%i, ch=%i, addr=%x, en=%02x\n",
// *(unsigned short *)&ch->regs[2], step, mul_l, mul_r, i, addr, Pico_mcd->pcm.enabled);
if (!stereo && mul_l < mul_r) mul_l = mul_r;