cog/Frameworks/GME/gme/okim6258.c

541 lines
14 KiB
C

/**********************************************************************************************
*
* OKI MSM6258 ADPCM
*
* TODO:
* 3-bit ADPCM support
* Recording?
*
**********************************************************************************************/
//#include "emu.h"
#include "mamedef.h"
#ifdef _DEBUG
#include <stdio.h>
#endif
//#include "streams.h"
#include <math.h>
#include <stdlib.h>
#include "okim6258.h"
#define COMMAND_STOP (1 << 0)
#define COMMAND_PLAY (1 << 1)
#define COMMAND_RECORD (1 << 2)
#define STATUS_PLAYING (1 << 1)
#define STATUS_RECORDING (1 << 2)
static const int dividers[4] = { 1024, 768, 512, 512 };
typedef struct _okim6258_state okim6258_state;
struct _okim6258_state
{
UINT8 status;
UINT32 master_clock; /* master clock frequency */
UINT32 divider; /* master clock divider */
UINT8 adpcm_type; /* 3/4 bit ADPCM select */
UINT8 data_in; /* ADPCM data-in register */
UINT8 nibble_shift; /* nibble select */
//sound_stream *stream; /* which stream are we playing on? */
UINT8 output_bits;
// Valley Bell: Added a small queue to prevent race conditions.
UINT8 data_buf[2];
UINT8 data_buf_pos;
// Data Empty Values:
// 00 - data written, but not read yet
// 01 - read data, waiting for next write
// 02 - tried to read, but had no data
UINT8 data_empty;
// Valley Bell: Added pan
UINT8 pan;
INT32 last_smpl;
INT32 signal;
INT32 step;
UINT8 clock_buffer[0x04];
UINT32 initial_clock;
UINT8 initial_div;
};
/* step size index shift table */
static const int index_shift[8] = { -1, -1, -1, -1, 2, 4, 6, 8 };
/* lookup table for the precomputed difference */
static int diff_lookup[49*16];
/* tables computed? */
static int tables_computed = 0;
/*INLINE okim6258_state *get_safe_token(running_device *device)
{
assert(device != NULL);
assert(device->type() == OKIM6258);
return (okim6258_state *)downcast<legacy_device_base *>(device)->token();
}*/
/**********************************************************************************************
compute_tables -- compute the difference tables
***********************************************************************************************/
static void compute_tables(void)
{
/* nibble to bit map */
static const int nbl2bit[16][4] =
{
{ 1, 0, 0, 0}, { 1, 0, 0, 1}, { 1, 0, 1, 0}, { 1, 0, 1, 1},
{ 1, 1, 0, 0}, { 1, 1, 0, 1}, { 1, 1, 1, 0}, { 1, 1, 1, 1},
{-1, 0, 0, 0}, {-1, 0, 0, 1}, {-1, 0, 1, 0}, {-1, 0, 1, 1},
{-1, 1, 0, 0}, {-1, 1, 0, 1}, {-1, 1, 1, 0}, {-1, 1, 1, 1}
};
int step, nib;
if (tables_computed)
return;
/* loop over all possible steps */
for (step = 0; step <= 48; step++)
{
/* compute the step value */
int stepval = floor(16.0 * pow(11.0 / 10.0, (double)step));
/* loop over all nibbles and compute the difference */
for (nib = 0; nib < 16; nib++)
{
diff_lookup[step*16 + nib] = nbl2bit[nib][0] *
(stepval * nbl2bit[nib][1] +
stepval/2 * nbl2bit[nib][2] +
stepval/4 * nbl2bit[nib][3] +
stepval/8);
}
}
tables_computed = 1;
}
static INT16 clock_adpcm(okim6258_state *chip, UINT8 nibble)
{
INT32 max = (1 << (chip->output_bits - 1)) - 1;
INT32 min = -(1 << (chip->output_bits - 1));
chip->signal += diff_lookup[chip->step * 16 + (nibble & 15)];
/* clamp to the maximum */
if (chip->signal > max)
chip->signal = max;
else if (chip->signal < min)
chip->signal = min;
/* adjust the step size and clamp */
chip->step += index_shift[nibble & 7];
if (chip->step > 48)
chip->step = 48;
else if (chip->step < 0)
chip->step = 0;
/* return the signal scaled up to 32767 */
return chip->signal << 4;
}
/**********************************************************************************************
okim6258_update -- update the sound chip so that it is in sync with CPU execution
***********************************************************************************************/
//static STREAM_UPDATE( okim6258_update )
void okim6258_update(void *_chip, stream_sample_t **outputs, int samples)
{
okim6258_state *chip = (okim6258_state *)_chip;
//stream_sample_t *buffer = outputs[0];
stream_sample_t *bufL = outputs[0];
stream_sample_t *bufR = outputs[1];
//memset(outputs[0], 0, samples * sizeof(*outputs[0]));
if (chip->status & STATUS_PLAYING)
{
int nibble_shift = chip->nibble_shift;
while (samples)
{
/* Compute the new amplitude and update the current step */
//int nibble = (chip->data_in >> nibble_shift) & 0xf;
int nibble;
INT16 sample;
if (! nibble_shift)
{
// 1st nibble - get data
if (! chip->data_empty)
{
chip->data_in = chip->data_buf[chip->data_buf_pos >> 4];
chip->data_buf_pos ^= 0x10;
if ((chip->data_buf_pos >> 4) == (chip->data_buf_pos & 0x0F))
chip->data_empty ++;
}
else
{
chip->data_in = 0x80;
if (chip->data_empty < 0x80)
chip->data_empty ++;
}
}
nibble = (chip->data_in >> nibble_shift) & 0xf;
/* Output to the buffer */
//INT16 sample = clock_adpcm(chip, nibble);
if (chip->data_empty < 0x02)
{
sample = clock_adpcm(chip, nibble);
chip->last_smpl = sample;
}
else
{
sample = chip->last_smpl;
// Valley Bell: data_empty behaviour (loosely) ported from XM6
if (chip->data_empty >= 0x12)
{
chip->data_empty -= 0x10;
if (chip->signal < 0)
chip->signal ++;
else if (chip->signal > 0)
chip->signal --;
}
}
nibble_shift ^= 4;
//*buffer++ = sample;
*bufL++ = (chip->pan & 0x02) ? 0x00 : sample;
*bufR++ = (chip->pan & 0x01) ? 0x00 : sample;
samples--;
}
/* Update the parameters */
chip->nibble_shift = nibble_shift;
}
else
{
/* Fill with 0 */
while (samples--)
{
//*buffer++ = 0;
*bufL++ = 0;
*bufR++ = 0;
}
}
}
/**********************************************************************************************
state save support for MAME
***********************************************************************************************/
/*static void okim6258_state_save_register(okim6258_state *info, running_device *device)
{
state_save_register_device_item(device, 0, info->status);
state_save_register_device_item(device, 0, info->master_clock);
state_save_register_device_item(device, 0, info->divider);
state_save_register_device_item(device, 0, info->data_in);
state_save_register_device_item(device, 0, info->nibble_shift);
state_save_register_device_item(device, 0, info->signal);
state_save_register_device_item(device, 0, info->step);
}*/
/**********************************************************************************************
OKIM6258_start -- start emulation of an OKIM6258-compatible chip
***********************************************************************************************/
//static DEVICE_START( okim6258 )
void * device_start_okim6258(int clock, int divider, int adpcm_type, int output_12bits)
{
//const okim6258_interface *intf = (const okim6258_interface *)device->baseconfig().static_config();
//okim6258_state *info = get_safe_token(device);
okim6258_state *info;
info = (okim6258_state *) calloc(1, sizeof(okim6258_state));
compute_tables();
//info->master_clock = device->clock();
info->initial_clock = clock;
info->initial_div = divider;
info->master_clock = clock;
info->adpcm_type = /*intf->*/adpcm_type;
info->clock_buffer[0x00] = (clock & 0x000000FF) >> 0;
info->clock_buffer[0x01] = (clock & 0x0000FF00) >> 8;
info->clock_buffer[0x02] = (clock & 0x00FF0000) >> 16;
info->clock_buffer[0x03] = (clock & 0xFF000000) >> 24;
/* D/A precision is 10-bits but 12-bit data can be output serially to an external DAC */
info->output_bits = /*intf->*/output_12bits ? 12 : 10;
info->divider = dividers[/*intf->*/divider];
//info->stream = stream_create(device, 0, 1, device->clock()/info->divider, info, okim6258_update);
info->signal = -2;
info->step = 0;
//okim6258_state_save_register(info, device);
return info; //return info->master_clock / info->divider;
}
/**********************************************************************************************
OKIM6258_stop -- stop emulation of an OKIM6258-compatible chip
***********************************************************************************************/
void device_stop_okim6258(void *chip)
{
okim6258_state *info = (okim6258_state *) chip;
free(info);
}
//static DEVICE_RESET( okim6258 )
void device_reset_okim6258(void *chip)
{
//okim6258_state *info = get_safe_token(device);
okim6258_state *info = (okim6258_state *) chip;
//stream_update(info->stream);
info->master_clock = info->initial_clock;
info->clock_buffer[0x00] = (info->initial_clock & 0x000000FF) >> 0;
info->clock_buffer[0x01] = (info->initial_clock & 0x0000FF00) >> 8;
info->clock_buffer[0x02] = (info->initial_clock & 0x00FF0000) >> 16;
info->clock_buffer[0x03] = (info->initial_clock & 0xFF000000) >> 24;
info->divider = dividers[info->initial_div];
info->signal = -2;
info->step = 0;
info->status = 0;
// Valley Bell: Added reset of the Data In register.
info->data_in = 0x00;
info->data_buf[0] = info->data_buf[1] = 0x00;
info->data_buf_pos = 0x00;
info->data_empty = 0xFF;
info->pan = 0x00;
}
/**********************************************************************************************
okim6258_set_divider -- set the master clock divider
***********************************************************************************************/
//void okim6258_set_divider(running_device *device, int val)
void okim6258_set_divider(void *chip, int val)
{
okim6258_state *info = (okim6258_state *) chip;
info->divider = dividers[val];
//stream_set_sample_rate(info->stream, info->master_clock / divider);
}
/**********************************************************************************************
okim6258_set_clock -- set the master clock
***********************************************************************************************/
//void okim6258_set_clock(running_device *device, int val)
void okim6258_set_clock(void *chip, int val)
{
okim6258_state *info = (okim6258_state *) chip;
if (val)
{
info->master_clock = val;
}
else
{
info->master_clock = (info->clock_buffer[0x00] << 0) |
(info->clock_buffer[0x01] << 8) |
(info->clock_buffer[0x02] << 16) |
(info->clock_buffer[0x03] << 24);
}
}
/**********************************************************************************************
okim6258_get_vclk -- get the VCLK/sampling frequency
***********************************************************************************************/
//int okim6258_get_vclk(running_device *device)
int okim6258_get_vclk(void *chip)
{
okim6258_state *info = (okim6258_state *) chip;
return (info->master_clock / info->divider);
}
/**********************************************************************************************
okim6258_status_r -- read the status port of an OKIM6258-compatible chip
***********************************************************************************************/
//READ8_DEVICE_HANDLER( okim6258_status_r )
UINT8 okim6258_status_r(void *chip, offs_t offset)
{
//okim6258_state *info = get_safe_token(device);
okim6258_state *info = (okim6258_state *) chip;
//stream_update(info->stream);
return (info->status & STATUS_PLAYING) ? 0x00 : 0x80;
}
/**********************************************************************************************
okim6258_data_w -- write to the control port of an OKIM6258-compatible chip
***********************************************************************************************/
//WRITE8_DEVICE_HANDLER( okim6258_data_w )
void okim6258_data_w(void *chip, offs_t offset, UINT8 data)
{
//okim6258_state *info = get_safe_token(device);
okim6258_state *info = (okim6258_state *) chip;
/* update the stream */
//stream_update(info->stream);
//info->data_in = data;
//info->nibble_shift = 0;
if (info->data_empty >= 0x02)
{
info->data_buf_pos = 0x00;
info->data_buf[info->data_buf_pos & 0x0F] = 0x80;
}
info->data_buf[info->data_buf_pos & 0x0F] = data;
info->data_buf_pos ^= 0x01;
info->data_empty = 0x00;
}
/**********************************************************************************************
okim6258_ctrl_w -- write to the control port of an OKIM6258-compatible chip
***********************************************************************************************/
//WRITE8_DEVICE_HANDLER( okim6258_ctrl_w )
void okim6258_ctrl_w(void *chip, offs_t offset, UINT8 data)
{
//okim6258_state *info = get_safe_token(device);
okim6258_state *info = (okim6258_state *) chip;
//stream_update(info->stream);
if (data & COMMAND_STOP)
{
info->status &= ~(STATUS_PLAYING | STATUS_RECORDING);
return;
}
if (data & COMMAND_PLAY)
{
if (!(info->status & STATUS_PLAYING))
{
info->status |= STATUS_PLAYING;
/* Also reset the ADPCM parameters */
//info->signal = -2;
//info->step = 0;
//info->nibble_shift = 0;
}
//info->signal = -2;
info->step = 0;
info->nibble_shift = 0;
}
else
{
info->status &= ~STATUS_PLAYING;
}
if (data & COMMAND_RECORD)
{
/*logerror("M6258: Record enabled\n");*/
info->status |= STATUS_RECORDING;
}
else
{
info->status &= ~STATUS_RECORDING;
}
}
void okim6258_set_clock_byte(void *chip, UINT8 Byte, UINT8 val)
{
okim6258_state *info = (okim6258_state *) chip;
info->clock_buffer[Byte] = val;
return;
}
static void okim6258_pan_w(void *chip, UINT8 data)
{
okim6258_state *info = (okim6258_state *) chip;
info->pan = data;
return;
}
void okim6258_write(void *chip, UINT8 Port, UINT8 Data)
{
switch(Port)
{
case 0x00:
okim6258_ctrl_w(chip, 0x00, Data);
break;
case 0x01:
okim6258_data_w(chip, 0x00, Data);
break;
case 0x02:
okim6258_pan_w(chip, Data);
break;
case 0x08:
case 0x09:
case 0x0A:
okim6258_set_clock_byte(chip, Port & 0x03, Data);
break;
case 0x0B:
okim6258_set_clock_byte(chip, Port & 0x03, Data);
okim6258_set_clock(chip, 0);
break;
case 0x0C:
okim6258_set_divider(chip, Data);
break;
}
}