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-rw-r--r--src/emu/sound/sp0250.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/src/emu/sound/sp0250.c b/src/emu/sound/sp0250.c
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+/*
+ GI SP0250 digital LPC sound synthesizer
+
+ By O. Galibert.
+
+ Unknown:
+ - Exact clock divider
+ - Exact noise algorithm
+ - Exact noise pitch (probably ok)
+ - 7 bits output mapping
+ - Whether the pitch starts counting from 0 or 1
+
+ Unimplemented:
+ - Direct Data test mode (pin 7)
+
+ Sound quite reasonably already though.
+*/
+
+#include <math.h>
+#include "sndintrf.h"
+#include "streams.h"
+#include "cpuintrf.h"
+#include "sp0250.h"
+
+/*
+standard external clock is 3.12MHz
+the chip provides a 445.7kHz output clock, which is = 3.12MHz / 7
+therefore I expect the clock divider to be a multiple of 7
+Also there are 6 cascading filter stages so I expect the divider to be a multiple of 6.
+
+The SP0250 manual states that the original speech is sampled at 10kHz, so the divider
+should be 312, but 312 = 39*8 so it doesn't look right because a divider by 39 is unlikely.
+
+7*6*8 = 336 gives a 9.286kHz sample rate and matches the samples from the Sega boards.
+*/
+#define CLOCK_DIVIDER (7*6*8)
+
+struct sp0250
+{
+ INT16 amp;
+ UINT8 pitch;
+ UINT8 repeat;
+ int pcount, rcount;
+ int playing;
+ UINT32 RNG;
+ sound_stream * stream;
+ int voiced;
+ UINT8 fifo[15];
+ int fifo_pos;
+
+ void (*drq)(int state);
+
+ struct
+ {
+ INT16 F, B;
+ INT16 z1, z2;
+ } filter[6];
+};
+
+
+static UINT16 sp0250_ga(UINT8 v)
+{
+ return (v & 0x1f) << (v>>5);
+}
+
+static INT16 sp0250_gc(UINT8 v)
+{
+ // Internal ROM to the chip, cf. manual
+ static const UINT16 coefs[128] =
+ {
+ 0, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97, 105, 113, 121,
+ 129, 137, 145, 153, 161, 169, 177, 185, 193, 201, 203, 217, 225, 233, 241, 249,
+ 257, 265, 273, 281, 289, 297, 301, 305, 309, 313, 317, 321, 325, 329, 333, 337,
+ 341, 345, 349, 353, 357, 361, 365, 369, 373, 377, 381, 385, 389, 393, 397, 401,
+ 405, 409, 413, 417, 421, 425, 427, 429, 431, 433, 435, 437, 439, 441, 443, 445,
+ 447, 449, 451, 453, 455, 457, 459, 461, 463, 465, 467, 469, 471, 473, 475, 477,
+ 479, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495,
+ 496, 497, 498, 499, 500, 501, 502, 503, 504, 505, 506, 507, 508, 509, 510, 511
+ };
+ INT16 res = coefs[v & 0x7f];
+
+ if (!(v & 0x80))
+ res = -res;
+ return res;
+}
+
+static void sp0250_load_values(struct sp0250 *sp)
+{
+ int f;
+
+
+ sp->filter[0].B = sp0250_gc(sp->fifo[ 0]);
+ sp->filter[0].F = sp0250_gc(sp->fifo[ 1]);
+ sp->amp = sp0250_ga(sp->fifo[ 2]);
+ sp->filter[1].B = sp0250_gc(sp->fifo[ 3]);
+ sp->filter[1].F = sp0250_gc(sp->fifo[ 4]);
+ sp->pitch = sp->fifo[ 5];
+ sp->filter[2].B = sp0250_gc(sp->fifo[ 6]);
+ sp->filter[2].F = sp0250_gc(sp->fifo[ 7]);
+ sp->repeat = sp->fifo[ 8] & 0x3f;
+ sp->voiced = sp->fifo[ 8] & 0x40;
+ sp->filter[3].B = sp0250_gc(sp->fifo[ 9]);
+ sp->filter[3].F = sp0250_gc(sp->fifo[10]);
+ sp->filter[4].B = sp0250_gc(sp->fifo[11]);
+ sp->filter[4].F = sp0250_gc(sp->fifo[12]);
+ sp->filter[5].B = sp0250_gc(sp->fifo[13]);
+ sp->filter[5].F = sp0250_gc(sp->fifo[14]);
+ sp->fifo_pos = 0;
+ sp->drq(ASSERT_LINE);
+
+ sp->pcount = 0;
+ sp->rcount = 0;
+
+ for (f = 0; f < 6; f++)
+ sp->filter[f].z1 = sp->filter[f].z2 = 0;
+
+ sp->playing = 1;
+}
+
+static TIMER_CALLBACK_PTR( sp0250_timer_tick )
+{
+ struct sp0250 *sp = param;
+ stream_update(sp->stream);
+}
+
+static void sp0250_update(void *param, stream_sample_t **inputs, stream_sample_t **buffer, int length)
+{
+ struct sp0250 *sp = param;
+ stream_sample_t *output = buffer[0];
+ int i;
+ for (i = 0; i < length; i++)
+ {
+ if (sp->playing)
+ {
+ INT16 z0;
+ int f;
+
+ if (sp->voiced)
+ {
+ if(!sp->pcount)
+ z0 = sp->amp;
+ else
+ z0 = 0;
+ }
+ else
+ {
+ // Borrowing the ay noise generation LFSR
+ if(sp->RNG & 1)
+ {
+ z0 = sp->amp;
+ sp->RNG ^= 0x24000;
+ }
+ else
+ z0 = -sp->amp;
+
+ sp->RNG >>= 1;
+ }
+
+ for (f = 0; f < 6; f++)
+ {
+ z0 += ((sp->filter[f].z1 * sp->filter[f].F) >> 8)
+ + ((sp->filter[f].z2 * sp->filter[f].B) >> 9);
+ sp->filter[f].z2 = sp->filter[f].z1;
+ sp->filter[f].z1 = z0;
+ }
+
+ // Physical resolution is only 7 bits, but heh
+
+ // max amplitude is 0x0f80 so we have margin to push up the output
+ output[i] = z0 << 3;
+
+ sp->pcount++;
+ if (sp->pcount >= sp->pitch)
+ {
+ sp->pcount = 0;
+ sp->rcount++;
+ if (sp->rcount >= sp->repeat)
+ sp->playing = 0;
+ }
+ }
+ else
+ output[i] = 0;
+
+ if (!sp->playing)
+ {
+ if(sp->fifo_pos == 15)
+ sp0250_load_values(sp);
+ }
+ }
+}
+
+
+static void *sp0250_start(int sndindex, int clock, const void *config)
+{
+ const struct sp0250_interface *intf = config;
+ struct sp0250 *sp;
+
+ sp = auto_malloc(sizeof(*sp));
+ memset(sp, 0, sizeof(*sp));
+ sp->RNG = 1;
+ sp->drq = intf->drq_callback;
+ sp->drq(ASSERT_LINE);
+ timer_pulse_ptr(attotime_mul(ATTOTIME_IN_HZ(clock), CLOCK_DIVIDER), sp, sp0250_timer_tick);
+
+ sp->stream = stream_create(0, 1, clock / CLOCK_DIVIDER, sp, sp0250_update);
+
+ return sp;
+}
+
+
+WRITE8_HANDLER( sp0250_w )
+{
+ struct sp0250 *sp = sndti_token(SOUND_SP0250, 0);
+ if (sp->fifo_pos != 15)
+ {
+ sp->fifo[sp->fifo_pos++] = data;
+ if (sp->fifo_pos == 15)
+ sp->drq(CLEAR_LINE);
+ }
+}
+
+
+
+/**************************************************************************
+ * Generic get_info
+ **************************************************************************/
+
+static void sp0250_set_info(void *token, UINT32 state, sndinfo *info)
+{
+ switch (state)
+ {
+ /* no parameters to set */
+ }
+}
+
+
+void sp0250_get_info(void *token, UINT32 state, sndinfo *info)
+{
+ switch (state)
+ {
+ /* --- the following bits of info are returned as 64-bit signed integers --- */
+
+ /* --- the following bits of info are returned as pointers to data or functions --- */
+ case SNDINFO_PTR_SET_INFO: info->set_info = sp0250_set_info; break;
+ case SNDINFO_PTR_START: info->start = sp0250_start; break;
+ case SNDINFO_PTR_STOP: /* Nothing */ break;
+ case SNDINFO_PTR_RESET: /* Nothing */ break;
+
+ /* --- the following bits of info are returned as NULL-terminated strings --- */
+ case SNDINFO_STR_NAME: info->s = "SP0250"; break;
+ case SNDINFO_STR_CORE_FAMILY: info->s = "GI speech"; break;
+ case SNDINFO_STR_CORE_VERSION: info->s = "1.1"; break;
+ case SNDINFO_STR_CORE_FILE: info->s = __FILE__; break;
+ case SNDINFO_STR_CORE_CREDITS: info->s = "Copyright (c) 2004, 2005 The MAME Team"; break;
+ }
+}
+