diff options
Diffstat (limited to 'trunk/src/emu/sound/tms3615.c')
-rw-r--r-- | trunk/src/emu/sound/tms3615.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/trunk/src/emu/sound/tms3615.c b/trunk/src/emu/sound/tms3615.c new file mode 100644 index 00000000000..5c263335fee --- /dev/null +++ b/trunk/src/emu/sound/tms3615.c @@ -0,0 +1,123 @@ +#include "emu.h" +#include "tms3615.h" + +#define VMIN 0x0000 +#define VMAX 0x7fff + +#define TONES 13 + +static const int divisor[TONES] = { 478, 451, 426, 402, 379, 358, 338, 319, 301, 284, 268, 253, 239 }; + +typedef struct _tms_state tms_state; +struct _tms_state { + sound_stream *channel; /* returned by stream_create() */ + int samplerate; /* output sample rate */ + int basefreq; /* chip's base frequency */ + int counter8[TONES]; /* tone frequency counter for 8' */ + int counter16[TONES]; /* tone frequency counter for 16'*/ + int output8; /* output signal bits for 8' */ + int output16; /* output signal bits for 16' */ + int enable; /* mask which tones to play */ +}; + +INLINE tms_state *get_safe_token(device_t *device) +{ + assert(device != NULL); + assert(device->type() == TMS3615); + return (tms_state *)downcast<legacy_device_base *>(device)->token(); +} + + +static STREAM_UPDATE( tms3615_sound_update ) +{ + tms_state *tms = (tms_state *)param; + int samplerate = tms->samplerate; + stream_sample_t *buffer8 = outputs[TMS3615_FOOTAGE_8]; + stream_sample_t *buffer16 = outputs[TMS3615_FOOTAGE_16]; + + while( samples-- > 0 ) + { + int sum8 = 0, sum16 = 0, tone = 0; + + for (tone = 0; tone < TONES; tone++) + { + // 8' + + tms->counter8[tone] -= (tms->basefreq / divisor[tone]); + + while( tms->counter8[tone] <= 0 ) + { + tms->counter8[tone] += samplerate; + tms->output8 ^= 1 << tone; + } + + if (tms->output8 & tms->enable & (1 << tone)) + { + sum8 += VMAX; + } + + // 16' + + tms->counter16[tone] -= (tms->basefreq / divisor[tone] / 2); + + while( tms->counter16[tone] <= 0 ) + { + tms->counter16[tone] += samplerate; + tms->output16 ^= 1 << tone; + } + + if (tms->output16 & tms->enable & (1 << tone)) + { + sum16 += VMAX; + } + } + + *buffer8++ = sum8 / TONES; + *buffer16++ = sum16 / TONES; + } + + tms->enable = 0; +} + +void tms3615_enable_w(device_t *device, int enable) +{ + tms_state *tms = get_safe_token(device); + tms->enable = enable; +} + +static DEVICE_START( tms3615 ) +{ + tms_state *tms = get_safe_token(device); + + tms->channel = device->machine().sound().stream_alloc(*device, 0, 2, device->clock()/8, tms, tms3615_sound_update); + tms->samplerate = device->clock()/8; + tms->basefreq = device->clock(); +} + +/************************************************************************** + * Generic get_info + **************************************************************************/ + +DEVICE_GET_INFO( tms3615 ) +{ + switch (state) + { + /* --- the following bits of info are returned as 64-bit signed integers --- */ + case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(tms_state); break; + + /* --- the following bits of info are returned as pointers to data or functions --- */ + case DEVINFO_FCT_START: info->start = DEVICE_START_NAME( tms3615 ); break; + case DEVINFO_FCT_STOP: /* Nothing */ break; + case DEVINFO_FCT_RESET: /* Nothing */ break; + + /* --- the following bits of info are returned as NULL-terminated strings --- */ + case DEVINFO_STR_NAME: strcpy(info->s, "TMS3615"); break; + case DEVINFO_STR_FAMILY: strcpy(info->s, "TI PSG"); break; + case DEVINFO_STR_VERSION: strcpy(info->s, "1.0"); break; + case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break; + case DEVINFO_STR_CREDITS: strcpy(info->s, "Copyright Nicola Salmoria and the MAME Team"); break; + } +} + + +DEFINE_LEGACY_SOUND_DEVICE(TMS3615, tms3615); |