diff options
Diffstat (limited to 'src/emu/sound/rf5c68.c')
-rw-r--r-- | src/emu/sound/rf5c68.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/src/emu/sound/rf5c68.c b/src/emu/sound/rf5c68.c new file mode 100644 index 00000000000..ad1c642734a --- /dev/null +++ b/src/emu/sound/rf5c68.c @@ -0,0 +1,260 @@ +/*********************************************************/ +/* ricoh RF5C68(or clone) PCM controller */ +/*********************************************************/ + +#include "sndintrf.h" +#include "streams.h" +#include "rf5c68.h" +#include <math.h> + + +#define NUM_CHANNELS (8) + + +struct pcm_channel +{ + UINT8 enable; + UINT8 env; + UINT8 pan; + UINT8 start; + UINT32 addr; + UINT16 step; + UINT16 loopst; +}; + + +struct rf5c68pcm +{ + sound_stream * stream; + struct pcm_channel chan[NUM_CHANNELS]; + UINT8 cbank; + UINT8 wbank; + UINT8 enable; + UINT8 data[0x10000]; +}; + + + +/************************************************/ +/* RF5C68 stream update */ +/************************************************/ + +static void rf5c68_update(void *param, stream_sample_t **inputs, stream_sample_t **buffer, int length) +{ + struct rf5c68pcm *chip = param; + stream_sample_t *left = buffer[0]; + stream_sample_t *right = buffer[1]; + int i, j; + + /* start with clean buffers */ + memset(left, 0, length * sizeof(*left)); + memset(right, 0, length * sizeof(*right)); + + /* bail if not enabled */ + if (!chip->enable) + return; + + /* loop over channels */ + for (i = 0; i < NUM_CHANNELS; i++) + { + struct pcm_channel *chan = &chip->chan[i]; + + /* if this channel is active, accumulate samples */ + if (chan->enable) + { + int lv = (chan->pan & 0x0f) * chan->env; + int rv = ((chan->pan >> 4) & 0x0f) * chan->env; + + /* loop over the sample buffer */ + for (j = 0; j < length; j++) + { + int sample; + + /* fetch the sample and handle looping */ + sample = chip->data[(chan->addr >> 11) & 0xffff]; + if (sample == 0xff) + { + chan->addr = chan->loopst << 11; + sample = chip->data[(chan->addr >> 11) & 0xffff]; + + /* if we loop to a loop point, we're effectively dead */ + if (sample == 0xff) + break; + } + chan->addr += chan->step; + + /* add to the buffer */ + if (sample & 0x80) + { + sample &= 0x7f; + left[j] += (sample * lv) >> 5; + right[j] += (sample * rv) >> 5; + } + else + { + left[j] -= (sample * lv) >> 5; + right[j] -= (sample * rv) >> 5; + } + } + } + } + + /* now clamp and shift the result (output is only 10 bits) */ + for (j = 0; j < length; j++) + { + stream_sample_t temp; + + temp = left[j]; + if (temp > 32767) temp = 32767; + else if (temp < -32768) temp = -32768; + left[j] = temp & ~0x3f; + + temp = right[j]; + if (temp > 32767) temp = 32767; + else if (temp < -32768) temp = -32768; + right[j] = temp & ~0x3f; + } +} + + +/************************************************/ +/* RF5C68 start */ +/************************************************/ + +static void *rf5c68_start(int sndindex, int clock, const void *config) +{ + /* allocate memory for the chip */ + struct rf5c68pcm *chip = auto_malloc(sizeof(*chip)); + memset(chip, 0, sizeof(*chip)); + memset(chip->data, 0xff, sizeof(chip->data)); + + /* allocate the stream */ + chip->stream = stream_create(0, 2, clock / 384, chip, rf5c68_update); + return chip; +} + + +/************************************************/ +/* RF5C68 write register */ +/************************************************/ + +WRITE8_HANDLER( RF5C68_reg_w ) +{ + struct rf5c68pcm *chip = sndti_token(SOUND_RF5C68, 0); + struct pcm_channel *chan = &chip->chan[chip->cbank]; + int i; + + /* force the stream to update first */ + stream_update(chip->stream); + + /* switch off the address */ + switch (offset) + { + case 0x00: /* envelope */ + chan->env = data; + break; + + case 0x01: /* pan */ + chan->pan = data; + break; + + case 0x02: /* FDL */ + chan->step = (chan->step & 0xff00) | (data & 0x00ff); + break; + + case 0x03: /* FDH */ + chan->step = (chan->step & 0x00ff) | ((data << 8) & 0xff00); + break; + + case 0x04: /* LSL */ + chan->loopst = (chan->loopst & 0xff00) | (data & 0x00ff); + break; + + case 0x05: /* LSH */ + chan->loopst = (chan->loopst & 0x00ff) | ((data << 8) & 0xff00); + break; + + case 0x06: /* ST */ + chan->start = data; + if (!chan->enable) + chan->addr = chan->start << (8 + 11); + break; + + case 0x07: /* control reg */ + chip->enable = (data >> 7) & 1; + if (data & 0x40) + chip->cbank = data & 7; + else + chip->wbank = data & 15; + break; + + case 0x08: /* channel on/off reg */ + for (i = 0; i < 8; i++) + { + chip->chan[i].enable = (~data >> i) & 1; + if (!chip->chan[i].enable) + chip->chan[i].addr = chip->chan[i].start << (8 + 11); + } + break; + } +} + + +/************************************************/ +/* RF5C68 read memory */ +/************************************************/ + +READ8_HANDLER( RF5C68_r ) +{ + struct rf5c68pcm *chip = sndti_token(SOUND_RF5C68, 0); + return chip->data[chip->wbank * 0x1000 + offset]; +} + + +/************************************************/ +/* RF5C68 write memory */ +/************************************************/ + +WRITE8_HANDLER( RF5C68_w ) +{ + struct rf5c68pcm *chip = sndti_token(SOUND_RF5C68, 0); + chip->data[chip->wbank * 0x1000 + offset] = data; +} + + + +/************************************************************************** + * Generic get_info + **************************************************************************/ + +static void rf5c68_set_info(void *token, UINT32 state, sndinfo *info) +{ + switch (state) + { + /* no parameters to set */ + } +} + + +void rf5c68_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 = rf5c68_set_info; break; + case SNDINFO_PTR_START: info->start = rf5c68_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 = "RF5C68"; break; + case SNDINFO_STR_CORE_FAMILY: info->s = "Ricoh PCM"; break; + case SNDINFO_STR_CORE_VERSION: info->s = "1.0"; break; + case SNDINFO_STR_CORE_FILE: info->s = __FILE__; break; + case SNDINFO_STR_CORE_CREDITS: info->s = "Copyright (c) 2004, The MAME Team"; break; + } +} + +/**************** end of file ****************/ |