/*********************************************************/ /* ricoh RF5C68(or clone) PCM controller */ /*********************************************************/ #include "emu.h" #include "rf5c68.h" #define NUM_CHANNELS (8) struct pcm_channel { UINT8 enable; UINT8 env; UINT8 pan; UINT8 start; UINT32 addr; UINT16 step; UINT16 loopst; }; struct rf5c68_state { sound_stream * stream; pcm_channel chan[NUM_CHANNELS]; UINT8 cbank; UINT8 wbank; UINT8 enable; UINT8 data[0x10000]; void (*sample_callback)(device_t* device,int channel); device_t* device; }; INLINE rf5c68_state *get_safe_token(device_t *device) { assert(device != NULL); assert(device->type() == RF5C68); return (rf5c68_state *)downcast(device)->token(); } /************************************************/ /* RF5C68 stream update */ /************************************************/ static STREAM_UPDATE( rf5c68_update ) { rf5c68_state *chip = (rf5c68_state *)param; stream_sample_t *left = outputs[0]; stream_sample_t *right = outputs[1]; int i, j; /* start with clean buffers */ memset(left, 0, samples * sizeof(*left)); memset(right, 0, samples * sizeof(*right)); /* bail if not enabled */ if (!chip->enable) return; /* loop over channels */ for (i = 0; i < NUM_CHANNELS; i++) { 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 < samples; j++) { int sample; /* trigger sample callback */ if(chip->sample_callback) { if(((chan->addr >> 11) & 0xfff) == 0xfff) chip->sample_callback(chip->device,((chan->addr >> 11)/0x2000)); } /* 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 < samples; 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 DEVICE_START( rf5c68 ) { const rf5c68_interface* intf = (const rf5c68_interface*)device->static_config(); /* allocate memory for the chip */ rf5c68_state *chip = get_safe_token(device); memset(chip->data, 0xff, sizeof(chip->data)); /* allocate the stream */ chip->stream = device->machine().sound().stream_alloc(*device, 0, 2, device->clock() / 384, chip, rf5c68_update); chip->device = device; /* set up callback */ if(intf != NULL) chip->sample_callback = intf->sample_end_callback; else chip->sample_callback = NULL; } /************************************************/ /* RF5C68 write register */ /************************************************/ READ8_DEVICE_HANDLER( rf5c68_r ) { rf5c68_state *chip = get_safe_token(device); UINT8 shift; chip->stream->update(); shift = (offset & 1) ? 11 + 8 : 11; // printf("%08x\n",(chip->chan[(offset & 0x0e) >> 1].addr)); return (chip->chan[(offset & 0x0e) >> 1].addr) >> (shift); } WRITE8_DEVICE_HANDLER( rf5c68_w ) { rf5c68_state *chip = get_safe_token(device); pcm_channel *chan = &chip->chan[chip->cbank]; int i; /* force the stream to update first */ chip->stream->update(); /* 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_DEVICE_HANDLER( rf5c68_mem_r ) { rf5c68_state *chip = get_safe_token(device); return chip->data[chip->wbank * 0x1000 + offset]; } /************************************************/ /* RF5C68 write memory */ /************************************************/ WRITE8_DEVICE_HANDLER( rf5c68_mem_w ) { rf5c68_state *chip = get_safe_token(device); chip->data[chip->wbank * 0x1000 + offset] = data; } const device_type RF5C68 = &device_creator; rf5c68_device::rf5c68_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, RF5C68, "RF5C68", tag, owner, clock), device_sound_interface(mconfig, *this) { m_token = global_alloc_clear(rf5c68_state); } //------------------------------------------------- // device_config_complete - perform any // operations now that the configuration is // complete //------------------------------------------------- void rf5c68_device::device_config_complete() { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void rf5c68_device::device_start() { DEVICE_START_NAME( rf5c68 )(this); } //------------------------------------------------- // sound_stream_update - handle a stream update //------------------------------------------------- void rf5c68_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) { // should never get here fatalerror("sound_stream_update called; not applicable to legacy sound devices\n"); }