Beispiel #1
0
void exidy_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
	sh6840_timer_channel *sh6840_timer = m_sh6840_timer;

	/* hack to skip the expensive lfsr noise generation unless at least one of the 3 channels actually depends on it being generated */
	int noisy = ((sh6840_timer[0].cr & sh6840_timer[1].cr & sh6840_timer[2].cr & 0x02) == 0);
	stream_sample_t *buffer = outputs[0];

	/* loop over samples */
	while (samples--)
	{
		sh6840_timer_channel *t;
		int clocks;
		stream_sample_t sample = 0;

		/* determine how many 6840 clocks this sample */
		m_sh6840_clock_count += m_sh6840_clocks_per_sample;
		int clocks_this_sample = m_sh6840_clock_count >> 24;
		m_sh6840_clock_count &= (1 << 24) - 1;

		/* skip if nothing enabled */
		if ((sh6840_timer[0].cr & 0x01) == 0)
		{
			int noise_clocks_this_sample = 0;
			uint32_t chan0_clocks;

			/* generate E-clocked noise if configured to do so */
			if (noisy && !(m_sfxctrl & 0x01))
				noise_clocks_this_sample = sh6840_update_noise(clocks_this_sample);

			/* handle timer 0 if enabled */
			t = &sh6840_timer[0];
			chan0_clocks = t->clocks;
			clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
			sh6840_apply_clock(t, clocks);
			if (t->state && !(m_sfxctrl & 0x02) && (t->cr & 0x80))
				sample += m_sh6840_volume[0];

			/* generate channel 0-clocked noise if configured to do so */
			if (noisy && (m_sfxctrl & 0x01))
				noise_clocks_this_sample = sh6840_update_noise(t->clocks - chan0_clocks);

			/* handle timer 1 if enabled */
			t = &sh6840_timer[1];
			clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
			sh6840_apply_clock(t, clocks);
			if (t->state && (t->cr & 0x80))
				sample += m_sh6840_volume[1];

			/* handle timer 2 if enabled */
			t = &sh6840_timer[2];
			clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
			/* prescale */
			if (t->cr & 0x01)
			{
				clocks += t->leftovers;
				t->leftovers = clocks % 8;
				clocks /= 8;
			}
			sh6840_apply_clock(t, clocks);
			if (t->state && (t->cr & 0x80))
				sample += m_sh6840_volume[2];
		}

		/* music (if present) */
		sample += generate_music_sample();

		/* stash */
		*buffer++ = sample;
	}
}
Beispiel #2
0
void beezer_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
	struct sh6840_timer_channel *sh6840_timer = m_sh6840_timer;

	/* hack to skip the expensive lfsr noise generation unless at least one of the 2 channels which actually depend on it are set to use it as a source */
	int noisy = ((sh6840_timer[0].cr & sh6840_timer[2].cr & 0x02) == 0);
	stream_sample_t *buffer = outputs[0];

	/* loop over samples */
	while (samples--)
	{
		struct sh6840_timer_channel *t;
		int clocks_this_sample;
		int clocks;
		INT16 sample1, sample2, sample3, sample0;
		INT16 sample = 0;
		sample1 = sample2 = sample3 = sample0 = 0;

		/* determine how many 6840 clocks this sample */
		m_sh6840_clock_count += m_sh6840_clocks_per_sample;
		clocks_this_sample = m_sh6840_clock_count >> 24;
		m_sh6840_clock_count &= (1 << 24) - 1;

		/* skip if nothing enabled */
		if ((sh6840_timer[0].cr & 0x01) == 0) // if we're not in reset...
		{
		// int noise_clocks_this_sample = 0;
			UINT32 chan1_clocks;

			/* generate noise if configured to do so */
			if (noisy != 0)
				sh6840_update_noise(clocks_this_sample);

			/* handle timer 0 if enabled */
			t = &sh6840_timer[0];
			clocks = (t->cr & 0x02) ? clocks_this_sample : m_sh6840_noiselatch1;
			sh6840_apply_clock(t, clocks);
			sample1 = (t->state && (t->cr & 0x80))?1:0;

			/* handle timer 1 if enabled */
			t = &sh6840_timer[1];
			chan1_clocks = t->clocks;
			clocks = (t->cr & 0x02) ? clocks_this_sample : 0; // TODO: this is WRONG: channel 1 is clocked by a mystery "VCO CLOCK" signal if not set to E clock. it may not even be connected to anything!
			sh6840_apply_clock(t, clocks);
			sample2 = (t->state && (t->cr & 0x80))?1:0;

			/* generate channel 1-clocked noise if configured to do so */
			if (noisy != 0)
			{
				sh6840_update_noise(t->clocks - chan1_clocks);
				if (clocks) m_sh6840_noiselatch3 = (m_sh6840_LFSR&0x1);
			}

			/* handle timer 2 if enabled */
			t = &sh6840_timer[2];
			clocks = (t->cr & 0x02) ? clocks_this_sample : m_sh6840_noiselatch3;
			/* prescale */
			if (t->cr & 0x01)
			{
				clocks += t->leftovers;
				t->leftovers = clocks % 8;
				clocks /= 8;
			}
			sh6840_apply_clock(t, clocks);
			sample3 = (t->state && (t->cr & 0x80))?1:0;
		}
		sample0 = m_sh6840_latchwrite?1:0;

		/* stash */
		/* each sample feeds an xor bit on the sign bit of a sign-magnitude (NOT 2'S COMPLEMENT)
		 * DAC. This requires some rather convoluted processing:
		 * samplex*0x80 brings the sample to the sign bit
		 * m_sh6840_volume[x]&0x80 pulls the sign bit from the dac sample
		 * m_sh6840_volume[x]&0x7F pulls the magnitude from the dac sample
		 */
		sample += (((sample0*0x80)^(m_sh6840_volume[0]&0x80))?-1:1)*(m_sh6840_volume[0]&0x7F);
		sample += (((sample1*0x80)^(m_sh6840_volume[1]&0x80))?-1:1)*(m_sh6840_volume[1]&0x7F);
		sample += (((sample2*0x80)^(m_sh6840_volume[2]&0x80))?-1:1)*(m_sh6840_volume[2]&0x7F);
		sample += (((sample3*0x80)^(m_sh6840_volume[3]&0x80))?-1:1)*(m_sh6840_volume[3]&0x7F);
		*buffer++ = sample*64; // adding 4 numbers ranging from -128 to 127 yields a range of -512 to 508; to scale that to '-32768 to 32767' we multiply by 64
	}
}
Beispiel #3
0
static void exidy_stream_update(void *param, stream_sample_t **inputs, stream_sample_t **outputs, int length)
{
	int noisy = ((sh6840_timer[0].cr & sh6840_timer[1].cr & sh6840_timer[2].cr & 0x02) == 0);
	stream_sample_t *buffer = outputs[0];

	/* loop over samples */
	while (length--)
	{
		struct sh6840_timer_channel *t;
		struct sh8253_timer_channel *c;
		int clocks_this_sample;
		INT16 sample = 0;

		/* determine how many 6840 clocks this sample */
		sh6840_clock_count += sh6840_clocks_per_sample;
		clocks_this_sample = sh6840_clock_count >> 24;
		sh6840_clock_count &= (1 << 24) - 1;

		/* skip if nothing enabled */
		if ((sh6840_timer[0].cr & 0x01) == 0)
		{
			int noise_clocks_this_sample = 0;
			UINT32 chan0_clocks;

			/* generate E-clocked noise if necessary */
			if (noisy && !(exidy_sfxctrl & 0x01))
				noise_clocks_this_sample = sh6840_update_noise(clocks_this_sample);

			/* handle timer 0 if enabled */
			t = &sh6840_timer[0];
			chan0_clocks = t->clocks;
			if (t->cr & 0x80)
			{
				int clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
				sh6840_apply_clock(t, clocks);
				if (t->state && !(exidy_sfxctrl & 0x02))
					sample += sh6840_volume[0];
			}

			/* generate channel 0-clocked noise if necessary */
			if (noisy && (exidy_sfxctrl & 0x01))
				noise_clocks_this_sample = sh6840_update_noise(t->clocks - chan0_clocks);

			/* handle timer 1 if enabled */
			t = &sh6840_timer[1];
			if (t->cr & 0x80)
			{
				int clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
				sh6840_apply_clock(t, clocks);
				if (t->state)
					sample += sh6840_volume[1];
			}

			/* handle timer 2 if enabled */
			t = &sh6840_timer[2];
			if (t->cr & 0x80)
			{
				int clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;

				/* prescale */
				if (t->cr & 0x01)
				{
					clocks += t->leftovers;
					t->leftovers = clocks % 8;
					clocks /= 8;
				}
				sh6840_apply_clock(t, clocks);
				if (t->state)
					sample += sh6840_volume[2];
			}
		}

		/* music (if present) */
		if (has_sh8253)
		{
			/* music channel 0 */
			c = &sh8253_timer[0];
			if (c->enable)
			{
				c->fraction += c->step;
				if (c->fraction & 0x0800000)
					sample += BASE_VOLUME;
			}

			/* music channel 1 */
			c = &sh8253_timer[1];
			if (c->enable)
			{
				c->fraction += c->step;
				if (c->fraction & 0x0800000)
					sample += BASE_VOLUME;
			}

			/* music channel 2 */
			c = &sh8253_timer[2];
			if (c->enable)
			{
				c->fraction += c->step;
				if (c->fraction & 0x0800000)
					sample += BASE_VOLUME;
			}
		}

		/* stash */
		*buffer++ = sample;
	}
}
Beispiel #4
0
static STREAM_UPDATE( exidy_stream_update )
{
	/* hack to skip the expensive lfsr noise generation unless at least one of the 3 channels actually depends on it being generated */
	int noisy = ((sh6840_timer[0].cr & sh6840_timer[1].cr & sh6840_timer[2].cr & 0x02) == 0);
	stream_sample_t *buffer = outputs[0];

	/* loop over samples */
	while (samples--)
	{
		struct sh6840_timer_channel *t;
		struct sh8253_timer_channel *c;
		int clocks_this_sample;
		int clocks;
		INT16 sample = 0;

		/* determine how many 6840 clocks this sample */
		sh6840_clock_count += sh6840_clocks_per_sample;
		clocks_this_sample = sh6840_clock_count >> 24;
		sh6840_clock_count &= (1 << 24) - 1;

		/* skip if nothing enabled */
		if ((sh6840_timer[0].cr & 0x01) == 0)
		{
			int noise_clocks_this_sample = 0;
			UINT32 chan0_clocks;

			/* generate E-clocked noise if configured to do so */
			if (noisy && !(exidy_sfxctrl & 0x01))
				noise_clocks_this_sample = sh6840_update_noise(clocks_this_sample);

			/* handle timer 0 if enabled */
			t = &sh6840_timer[0];
			chan0_clocks = t->clocks;
			clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
			sh6840_apply_clock(t, clocks);
			if (t->state && !(exidy_sfxctrl & 0x02) && (t->cr & 0x80))
				sample += sh6840_volume[0];

			/* generate channel 0-clocked noise if configured to do so */
			if (noisy && (exidy_sfxctrl & 0x01))
				noise_clocks_this_sample = sh6840_update_noise(t->clocks - chan0_clocks);

			/* handle timer 1 if enabled */
			t = &sh6840_timer[1];
			clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
			sh6840_apply_clock(t, clocks);
			if (t->state && (t->cr & 0x80))
				sample += sh6840_volume[1];

			/* handle timer 2 if enabled */
			t = &sh6840_timer[2];
			clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
			/* prescale */
			if (t->cr & 0x01)
			{
				clocks += t->leftovers;
				t->leftovers = clocks % 8;
				clocks /= 8;
			}
			sh6840_apply_clock(t, clocks);
			if (t->state && (t->cr & 0x80))
				sample += sh6840_volume[2];
		}

		/* music (if present) */
		if (has_sh8253)
		{
			/* music channel 0 */
			c = &sh8253_timer[0];
			if (c->enable)
			{
				c->fraction += c->step;
				if (c->fraction & 0x0800000)
					sample += BASE_VOLUME;
			}

			/* music channel 1 */
			c = &sh8253_timer[1];
			if (c->enable)
			{
				c->fraction += c->step;
				if (c->fraction & 0x0800000)
					sample += BASE_VOLUME;
			}

			/* music channel 2 */
			c = &sh8253_timer[2];
			if (c->enable)
			{
				c->fraction += c->step;
				if (c->fraction & 0x0800000)
					sample += BASE_VOLUME;
			}
		}

		/* stash */
		*buffer++ = sample;
	}
}