diff options
Diffstat (limited to 'src/devices/sound/c6280.cpp')
-rw-r--r-- | src/devices/sound/c6280.cpp | 356 |
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; } } |