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-rw-r--r--src/devices/sound/c6280.cpp356
1 files changed, 198 insertions, 158 deletions
diff --git a/src/devices/sound/c6280.cpp b/src/devices/sound/c6280.cpp
index 6c6f2410166..c156033dce8 100644
--- a/src/devices/sound/c6280.cpp
+++ b/src/devices/sound/c6280.cpp
@@ -24,12 +24,7 @@
- Verify LFO frequency from real hardware.
- - Add shared index for waveform playback and sample writes. Almost every
- game will reset the index prior to playback so this isn't an issue.
-
- - While the noise emulation is complete, the data for the pseudo-random
- bitstream is calculated by machine().rand() and is not a representation of what
- the actual hardware does.
+ - Noise generating algorithm is shared in all channels?
For some background on Hudson Soft's C62 chipset:
@@ -45,138 +40,133 @@
#include "emu.h"
#include "c6280.h"
+#include <algorithm>
-void c6280_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
+void c6280_device::sound_stream_update(sound_stream &stream)
{
- static const int scale_tab[] = {
- 0x00, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
- 0x10, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F
- };
-
- int lmal = (m_balance >> 4) & 0x0F;
- int rmal = (m_balance >> 0) & 0x0F;
+ // Fast method if none of the channels are enabled (most Data East arcade games)
+ if (!(m_enabled & 0x3f))
+ return;
- lmal = scale_tab[lmal];
- rmal = scale_tab[rmal];
-
- /* Clear buffer */
- for (int i = 0; i < samples; i++)
+ static const u8 scale_tab[16] =
{
- outputs[0][i] = 0;
- outputs[1][i] = 0;
- }
+ 0x00, 0x03, 0x05, 0x07, 0x09, 0x0b, 0x0d, 0x0f,
+ 0x10, 0x13, 0x15, 0x17, 0x19, 0x1b, 0x1d, 0x1f
+ };
- for (int ch = 0; ch < 6; ch++)
+ const u8 lmal = scale_tab[(m_balance >> 4) & 0x0f];
+ const u8 rmal = scale_tab[(m_balance >> 0) & 0x0f];
+
+ for (int i = 0; i < stream.samples(); i++)
{
- /* Only look at enabled channels */
- if(m_channel[ch].m_control & 0x80)
+ s32 lout = 0, rout = 0;
+ for (int ch = 0; ch < 6; ch++)
{
- int lal = (m_channel[ch].m_balance >> 4) & 0x0F;
- int ral = (m_channel[ch].m_balance >> 0) & 0x0F;
- int al = m_channel[ch].m_control & 0x1F;
+ // Only look at enabled channels
+ if (BIT(m_enabled, ch))
+ {
+ channel &chan = m_channel[ch];
- lal = scale_tab[lal];
- ral = scale_tab[ral];
+ const u8 lal = scale_tab[(chan.balance >> 4) & 0x0f];
+ const u8 ral = scale_tab[(chan.balance >> 0) & 0x0f];
+ const u8 al = chan.control & 0x1f;
- /* Calculate volume just as the patent says */
- int vll = (0x1F - lal) + (0x1F - al) + (0x1F - lmal);
- if(vll > 0x1F) vll = 0x1F;
+ // Verified from both patent and manual
+ int vll = (0x1f - lmal) + (0x1f - al) + (0x1f - lal);
+ if (vll > 0x1f) vll = 0x1f;
- int vlr = (0x1F - ral) + (0x1F - al) + (0x1F - rmal);
- if(vlr > 0x1F) vlr = 0x1F;
+ int vlr = (0x1f - rmal) + (0x1f - al) + (0x1f - ral);
+ if (vlr > 0x1f) vlr = 0x1f;
- vll = m_volume_table[vll];
- vlr = m_volume_table[vlr];
+ vll = m_volume_table[vll];
+ vlr = m_volume_table[vlr];
- /* Check channel mode */
- if((ch >= 4) && (m_channel[ch].m_noise_control & 0x80))
- {
- /* Noise mode */
- uint32_t step = (m_channel[ch].m_noise_control & 0x1F) ^ 0x1F;
- for (int i = 0; i < samples; i += 1)
+ // Check channel mode
+ if ((ch >= 4) && BIT(chan.noise_control, 7))
{
- static int data = 0;
- if(m_channel[ch].m_noise_counter <= 0)
+ // Noise mode
+ const u32 step = (chan.noise_control & 0x1f) ^ 0x1f;
+ const s16 data = BIT(chan.noise_seed, 0) ? 0x1f : 0;
+ chan.noise_counter--;
+ if (chan.noise_counter <= 0)
{
- m_channel[ch].m_noise_counter = step << 2;
- data = (machine().rand() & 1) ? 0x1F : 0;
+ chan.noise_counter = step << 6; // 32 * 2
+ const u32 seed = chan.noise_seed;
+ // based on Charles MacDonald's research
+ chan.noise_seed = (seed >> 1) | ((BIT(seed, 0) ^ BIT(seed, 1) ^ BIT(seed, 11) ^ BIT(seed, 12) ^ BIT(seed, 17)) << 17);
}
- m_channel[ch].m_noise_counter--;
- outputs[0][i] += (int16_t)(vll * (data - 16));
- outputs[1][i] += (int16_t)(vlr * (data - 16));
+ lout += vll * (data - 16);
+ rout += vlr * (data - 16);
}
- }
- else
- if(m_channel[ch].m_control & 0x40)
- {
- /* DDA mode */
- for (int i = 0; i < samples; i++)
+ else if (BIT(chan.control, 6))
{
- outputs[0][i] += (int16_t)(vll * (m_channel[ch].m_dda - 16));
- outputs[1][i] += (int16_t)(vlr * (m_channel[ch].m_dda - 16));
+ // DDA mode
+ lout += vll * (chan.dda - 16);
+ rout += vlr * (chan.dda - 16);
}
- }
- else
- {
- if ((m_lfo_control & 3) && (ch < 2))
+ else
{
- if (ch == 0) // CH 0 only, CH 1 is muted
+ if ((m_lfo_control & 3) && (ch < 2))
{
- /* Waveform mode with LFO */
- uint16_t lfo_step = m_channel[1].m_frequency ? m_channel[1].m_frequency : 0x1000;
- for (int i = 0; i < samples; i += 1)
+ if (ch == 0)
{
- int32_t step = m_channel[0].m_frequency ? m_channel[0].m_frequency : 0x1000;
- if (m_lfo_control & 0x80) // reset LFO
+ // Waveform mode with LFO
+ channel &lfo_srcchan = m_channel[1];
+ channel &lfo_dstchan = m_channel[0];
+ const u16 lfo_step = lfo_srcchan.frequency ? lfo_srcchan.frequency : 0x1000;
+ s32 step = lfo_dstchan.frequency ? lfo_dstchan.frequency : 0x1000;
+ if (BIT(m_lfo_control, 7)) // reset LFO
{
- m_channel[1].m_tick = lfo_step * m_lfo_frequency;
- m_channel[1].m_counter = 0;
+ lfo_srcchan.tick = lfo_step * m_lfo_frequency;
+ lfo_srcchan.index = 0;
}
else
{
- int lfooffset = m_channel[1].m_counter;
- m_channel[1].m_tick--;
- if (m_channel[1].m_tick <= 0)
+ const s16 lfo_data = lfo_srcchan.waveform[lfo_srcchan.index];
+ lfo_srcchan.tick--;
+ if (lfo_srcchan.tick <= 0)
{
- m_channel[1].m_tick = lfo_step * m_lfo_frequency; // TODO : multiply? verify this from real hardware.
- m_channel[1].m_counter = (m_channel[1].m_counter + 1) & 0x1f;
+ lfo_srcchan.tick = lfo_step * m_lfo_frequency; // verified from manual
+ lfo_srcchan.index = (lfo_srcchan.index + 1) & 0x1f;
}
- int16_t lfo_data = m_channel[1].m_waveform[lfooffset];
- step += ((lfo_data - 16) << (((m_lfo_control & 3)-1)<<1)); // verified from patent, TODO : same in real hardware?
+ step += ((lfo_data - 16) << (((m_lfo_control & 3) - 1) << 1)); // verified from manual
}
- int offset = m_channel[0].m_counter;
- m_channel[0].m_tick--;
- if (m_channel[0].m_tick <= 0)
+ const s16 data = lfo_dstchan.waveform[lfo_dstchan.index];
+ lfo_dstchan.tick--;
+ if (lfo_dstchan.tick <= 0)
{
- m_channel[0].m_tick = step;
- m_channel[0].m_counter = (m_channel[0].m_counter + 1) & 0x1f;
+ lfo_dstchan.tick = step;
+ lfo_dstchan.index = (lfo_dstchan.index + 1) & 0x1f;
}
- int16_t data = m_channel[0].m_waveform[offset];
- outputs[0][i] += (int16_t)(vll * (data - 16));
- outputs[1][i] += (int16_t)(vlr * (data - 16));
+ lout += vll * (data - 16);
+ rout += vlr * (data - 16);
+ }
+ else if (ch == 1) // NOT muted even when LFO is on
+ {
+ const s16 data = chan.waveform[chan.index];
+ lout += vll * (data - 16);
+ rout += vlr * (data - 16);
}
}
- }
- else
- {
- /* Waveform mode */
- uint32_t step = m_channel[ch].m_frequency ? m_channel[ch].m_frequency : 0x1000;
- for (int i = 0; i < samples; i += 1)
+ else
{
- int offset = m_channel[ch].m_counter;
- m_channel[ch].m_tick--;
- if (m_channel[ch].m_tick <= 0)
+ // Waveform mode
+ const u32 step = chan.frequency ? chan.frequency : 0x1000;
+ const s16 data = chan.waveform[chan.index];
+ chan.tick--;
+ if (chan.tick <= 0)
{
- m_channel[ch].m_tick = step;
- m_channel[ch].m_counter = (m_channel[ch].m_counter + 1) & 0x1f;
+ chan.tick = step;
+ chan.index = (chan.index + 1) & 0x1f;
}
- int16_t data = m_channel[ch].m_waveform[offset];
- outputs[0][i] += (int16_t)(vll * (data - 16));
- outputs[1][i] += (int16_t)(vlr * (data - 16));
+ lout += vll * (data - 16);
+ rout += vlr * (data - 16);
}
}
}
}
+ stream.put_int(0, i, lout, 32768);
+ stream.put_int(1, i, rout, 32768);
}
}
@@ -185,84 +175,123 @@ void c6280_device::sound_stream_update(sound_stream &stream, stream_sample_t **i
/* MAME specific code */
/*--------------------------------------------------------------------------*/
-WRITE8_MEMBER( c6280_device::c6280_w )
+/* Write Register Layout
+
+ 76543210
+ 00 -----xxx Channel Select
+ -----000 Channel 0
+ -----001 Channel 1
+ -----010 Channel 2
+ -----011 Channel 3
+ -----100 Channel 4
+ -----101 Channel 5
+
+ 01 xxxx---- Overall Left Volume
+ ----xxxx Overall Right Volume
+
+ 02 xxxxxxxx Frequency (Low 8 bits)
+
+ 03 ----xxxx Frequency (High 4 bits)
+
+ 04 x------- Channel Enable
+ -x------ Direct D/A
+ 00------ Write Data
+ 01------ Reset Counter
+ 10------ Mixing (Sound Output)
+ 11------ Direct D/A
+ ---xxxxx Channel Master Volume
+
+ 05 xxxx---- Channel Left Volume
+ ----xxxx Channel Right Volume
+
+ 06 ---xxxxx Waveform Data
+
+ 07 x------- Noise Enable (channel 5, 6 only)
+ ---xxxxx Noise Frequency ^ 0x1f
+
+ 08 xxxxxxxx LFO Frequency
+
+ 09 x------- LFO Reset
+ ------xx LFO Control
+ ------00 LFO off
+ ------01 Direct Addition
+ ------10 2 bit Shift Addition
+ ------11 4 bit Shift Addition
+*/
+
+void c6280_device::c6280_w(offs_t offset, uint8_t data)
{
- channel *chan = &m_channel[m_select];
+ channel &chan = m_channel[m_select];
- /* Update stream */
+ // Update stream
m_stream->update();
- switch(offset & 0x0F)
+ switch (offset & 0x0f)
{
- case 0x00: /* Channel select */
+ case 0x00: // Channel select
m_select = data & 0x07;
break;
- case 0x01: /* Global balance */
- m_balance = data;
+ case 0x01: // Global balance
+ m_balance = data;
break;
- case 0x02: /* Channel frequency (LSB) */
- chan->m_frequency = (chan->m_frequency & 0x0F00) | data;
- chan->m_frequency &= 0x0FFF;
+ case 0x02: // Channel frequency (LSB)
+ chan.frequency = (chan.frequency & 0x0f00) | data;
break;
- case 0x03: /* Channel frequency (MSB) */
- chan->m_frequency = (chan->m_frequency & 0x00FF) | (data << 8);
- chan->m_frequency &= 0x0FFF;
+ case 0x03: // Channel frequency (MSB)
+ chan.frequency = (chan.frequency & 0x00ff) | ((data << 8) & 0x0f00);
break;
- case 0x04: /* Channel control (key-on, DDA mode, volume) */
+ case 0x04: // Channel control (key-on, DDA mode, volume)
- /* 1-to-0 transition of DDA bit resets waveform index */
- if((chan->m_control & 0x40) && ((data & 0x40) == 0))
+ // 1-to-0 transition of DDA bit resets waveform index
+ if (BIT(chan.control, 6) && BIT(~data, 6))
{
- chan->m_index = 0;
+ chan.index = 0;
}
- if(((chan->m_control & 0x80) == 0) && (data & 0x80))
+ if (BIT(~chan.control, 7) && BIT(data, 7))
{
- chan->m_tick = chan->m_frequency;
+ chan.tick = chan.frequency;
}
- chan->m_control = data;
+ chan.control = data;
+
+ // Cache channel enable flag
+ m_enabled &= ~(1 << m_select);
+ m_enabled |= BIT(data, 7) << m_select;
break;
- case 0x05: /* Channel balance */
- chan->m_balance = data;
+ case 0x05: // Channel balance
+ chan.balance = data;
break;
- case 0x06: /* Channel waveform data */
+ case 0x06: // Channel waveform data
- switch(chan->m_control & 0xC0)
+ switch (chan.control & 0x40)
{
- case 0x00:
- chan->m_waveform[chan->m_index & 0x1F] = data & 0x1F;
- chan->m_index = (chan->m_index + 1) & 0x1F;
- break;
-
- case 0x40:
- break;
-
- case 0x80:
- chan->m_waveform[chan->m_index & 0x1F] = data & 0x1F;
- chan->m_index = (chan->m_index + 1) & 0x1F;
+ case 0x00: // Waveform
+ chan.waveform[chan.index & 0x1f] = data & 0x1f;
+ if (BIT(~chan.control, 7)) // TODO : wave pointer is increased at writing data when sound playback is off??
+ chan.index = (chan.index + 1) & 0x1f;
break;
- case 0xC0:
- chan->m_dda = data & 0x1F;
+ case 0x40: // Direct D/A
+ chan.dda = data & 0x1f;
break;
}
break;
- case 0x07: /* Noise control (enable, frequency) */
- chan->m_noise_control = data;
+ case 0x07: // Noise control (enable, frequency)
+ chan.noise_control = data;
break;
- case 0x08: /* LFO frequency */
+ case 0x08: // LFO frequency
m_lfo_frequency = data;
break;
- case 0x09: /* LFO control (enable, mode) */
+ case 0x09: // LFO control (enable, mode)
m_lfo_control = data;
break;
@@ -273,7 +302,7 @@ WRITE8_MEMBER( c6280_device::c6280_w )
DEFINE_DEVICE_TYPE(C6280, c6280_device, "c6280", "Hudson Soft HuC6280 PSG")
-c6280_device::c6280_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+c6280_device::c6280_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
: device_t(mconfig, C6280, tag, owner, clock)
, device_sound_interface(mconfig, *this)
{
@@ -290,43 +319,54 @@ void c6280_device::device_clock_changed()
void c6280_device::device_start()
{
- /* Loudest volume level for table */
+ // Loudest volume level for table
double level = 65535.0 / 6.0 / 32.0;
- /* Clear context */
+ // Clear context
m_select = 0;
+ m_enabled = 0;
m_balance = 0;
m_lfo_frequency = 0;
m_lfo_control = 0;
memset(m_channel, 0, sizeof(channel) * 8);
- m_stream = machine().sound().stream_alloc(*this, 0, 2, clock());
+ m_stream = stream_alloc(0, 2, clock());
- /* Make volume table */
- /* PSG has 48dB volume range spread over 32 steps */
+ // Make volume table
+ // PSG has 48dB volume range spread over 32 steps
double step = 48.0 / 32.0;
for (int i = 0; i < 31; i++)
{
- m_volume_table[i] = (uint16_t)level;
+ m_volume_table[i] = (u16)level;
level /= pow(10.0, step / 20.0);
}
m_volume_table[31] = 0;
save_item(NAME(m_select));
+ save_item(NAME(m_enabled));
save_item(NAME(m_balance));
save_item(NAME(m_lfo_frequency));
save_item(NAME(m_lfo_control));
- for (int chan = 0; chan < 8; chan++)
+
+ save_item(STRUCT_MEMBER(m_channel, frequency));
+ save_item(STRUCT_MEMBER(m_channel, control));
+ save_item(STRUCT_MEMBER(m_channel, balance));
+ save_item(STRUCT_MEMBER(m_channel, waveform));
+ save_item(STRUCT_MEMBER(m_channel, index));
+ save_item(STRUCT_MEMBER(m_channel, dda));
+ save_item(STRUCT_MEMBER(m_channel, noise_control));
+ save_item(STRUCT_MEMBER(m_channel, noise_counter));
+ save_item(STRUCT_MEMBER(m_channel, noise_seed));
+ save_item(STRUCT_MEMBER(m_channel, tick));
+}
+
+void c6280_device::device_reset()
+{
+ for (int ch = 0; ch < 6; ch++)
{
- save_item(NAME(m_channel[chan].m_frequency), chan);
- save_item(NAME(m_channel[chan].m_control), chan);
- save_item(NAME(m_channel[chan].m_balance), chan);
- save_item(NAME(m_channel[chan].m_waveform), chan);
- save_item(NAME(m_channel[chan].m_index), chan);
- save_item(NAME(m_channel[chan].m_dda), chan);
- save_item(NAME(m_channel[chan].m_noise_control), chan);
- save_item(NAME(m_channel[chan].m_noise_counter), chan);
- save_item(NAME(m_channel[chan].m_counter), chan);
- save_item(NAME(m_channel[chan].m_tick), chan);
+ channel &chan = m_channel[ch];
+ chan.index = 0;
+ if (ch >= 4)
+ chan.noise_seed = 1;
}
}