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Diffstat (limited to '3rdparty/ymfm/src/ymfm_opq.cpp')
-rw-r--r-- | 3rdparty/ymfm/src/ymfm_opq.cpp | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/3rdparty/ymfm/src/ymfm_opq.cpp b/3rdparty/ymfm/src/ymfm_opq.cpp new file mode 100644 index 00000000000..78ae1616409 --- /dev/null +++ b/3rdparty/ymfm/src/ymfm_opq.cpp @@ -0,0 +1,480 @@ +// BSD 3-Clause License +// +// Copyright (c) 2021, Aaron Giles +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this +// list of conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE +// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "ymfm_opq.h" +#include "ymfm_fm.ipp" + +#define TEMPORARY_DEBUG_PRINTS (0) + +// +// OPQ (aka YM3806/YM3533) +// +// This chip is not officially documented as far as I know. What I have +// comes from Jari Kangas' work on reverse engineering the PSR70: +// +// https://github.com/JKN0/PSR70-reverse +// +// OPQ appears be bsaically a mixture of OPM and OPN. +// + +namespace ymfm +{ + +//********************************************************* +// OPQ SPECIFICS +//********************************************************* + +//------------------------------------------------- +// opq_registers - constructor +//------------------------------------------------- + +opq_registers::opq_registers() : + m_lfo_counter(0), + m_lfo_am(0) +{ + // create the waveforms + for (uint32_t index = 0; index < WAVEFORM_LENGTH; index++) + m_waveform[0][index] = abs_sin_attenuation(index) | (bitfield(index, 9) << 15); + + uint16_t zeroval = m_waveform[0][0]; + for (uint32_t index = 0; index < WAVEFORM_LENGTH; index++) + m_waveform[1][index] = bitfield(index, 9) ? zeroval : m_waveform[0][index]; +} + + +//------------------------------------------------- +// reset - reset to initial state +//------------------------------------------------- + +void opq_registers::reset() +{ + std::fill_n(&m_regdata[0], REGISTERS, 0); + + // enable output on both channels by default + m_regdata[0x10] = m_regdata[0x11] = m_regdata[0x12] = m_regdata[0x13] = 0xc0; + m_regdata[0x14] = m_regdata[0x15] = m_regdata[0x16] = m_regdata[0x17] = 0xc0; +} + + +//------------------------------------------------- +// save_restore - save or restore the data +//------------------------------------------------- + +void opq_registers::save_restore(ymfm_saved_state &state) +{ + state.save_restore(m_lfo_counter); + state.save_restore(m_lfo_am); + state.save_restore(m_regdata); +} + + +//------------------------------------------------- +// operator_map - return an array of operator +// indices for each channel; for OPM this is fixed +//------------------------------------------------- + +void opq_registers::operator_map(operator_mapping &dest) const +{ + // seems like the operators are not swizzled like they are on OPM/OPN? + static const operator_mapping s_fixed_map = + { { + operator_list( 0, 8, 16, 24 ), // Channel 0 operators + operator_list( 1, 9, 17, 25 ), // Channel 1 operators + operator_list( 2, 10, 18, 26 ), // Channel 2 operators + operator_list( 3, 11, 19, 27 ), // Channel 3 operators + operator_list( 4, 12, 20, 28 ), // Channel 4 operators + operator_list( 5, 13, 21, 29 ), // Channel 5 operators + operator_list( 6, 14, 22, 30 ), // Channel 6 operators + operator_list( 7, 15, 23, 31 ), // Channel 7 operators + } }; + dest = s_fixed_map; +} + + +//------------------------------------------------- +// write - handle writes to the register array +//------------------------------------------------- + +bool opq_registers::write(uint16_t index, uint8_t data, uint32_t &channel, uint32_t &opmask) +{ + assert(index < REGISTERS); + + // detune/multiple share a register based on the MSB of what is written + // remap the multiple values to 100-11F + if ((index & 0xe0) == 0x40 && bitfield(data, 7) != 0) + index += 0xc0; + + m_regdata[index] = data; + + // handle writes to the key on index + if (index == 0x05) + { + channel = bitfield(data, 0, 3); + opmask = bitfield(data, 3, 4); + return true; + } + return false; +} + + +//------------------------------------------------- +// clock_noise_and_lfo - clock the noise and LFO, +// handling clock division, depth, and waveform +// computations +//------------------------------------------------- + +int32_t opq_registers::clock_noise_and_lfo() +{ + // OPQ LFO is not well-understood, but the enable and rate values + // look a lot like OPN, so we'll crib from there as a starting point + + // if LFO not enabled (not present on OPN), quick exit with 0s + if (!lfo_enable()) + { + m_lfo_counter = 0; + m_lfo_am = 0; + return 0; + } + + // this table is based on converting the frequencies in the applications + // manual to clock dividers, based on the assumption of a 7-bit LFO value + static uint8_t const lfo_max_count[8] = { 109, 78, 72, 68, 63, 45, 9, 6 }; + uint32_t subcount = uint8_t(m_lfo_counter++); + + // when we cross the divider count, add enough to zero it and cause an + // increment at bit 8; the 7-bit value lives from bits 8-14 + if (subcount >= lfo_max_count[lfo_rate()]) + m_lfo_counter += 0x101 - subcount; + + // AM value is 7 bits, staring at bit 8; grab the low 6 directly + m_lfo_am = bitfield(m_lfo_counter, 8, 6); + + // first half of the AM period (bit 6 == 0) is inverted + if (bitfield(m_lfo_counter, 8+6) == 0) + m_lfo_am ^= 0x3f; + + // PM value is 5 bits, starting at bit 10; grab the low 3 directly + int32_t pm = bitfield(m_lfo_counter, 10, 3); + + // PM is reflected based on bit 3 + if (bitfield(m_lfo_counter, 10+3)) + pm ^= 7; + + // PM is negated based on bit 4 + return bitfield(m_lfo_counter, 10+4) ? -pm : pm; +} + + +//------------------------------------------------- +// lfo_am_offset - return the AM offset from LFO +// for the given channel +//------------------------------------------------- + +uint32_t opq_registers::lfo_am_offset(uint32_t choffs) const +{ + // OPM maps AM quite differently from OPN + + // shift value for AM sensitivity is [*, 0, 1, 2], + // mapping to values of [0, 23.9, 47.8, and 95.6dB] + uint32_t am_sensitivity = ch_lfo_am_sens(choffs); + if (am_sensitivity == 0) + return 0; + + // QUESTION: see OPN note below for the dB range mapping; it applies + // here as well + + // raw LFO AM value on OPM is 0-FF, which is already a factor of 2 + // larger than the OPN below, putting our staring point at 2x theirs; + // this works out since our minimum is 2x their maximum + return m_lfo_am << (am_sensitivity - 1); +} + + +//------------------------------------------------- +// cache_operator_data - fill the operator cache +// with prefetched data +//------------------------------------------------- + +void opq_registers::cache_operator_data(uint32_t choffs, uint32_t opoffs, opdata_cache &cache) +{ + // set up the easy stuff + cache.waveform = &m_waveform[op_waveform(opoffs)][0]; + + // get frequency from the appropriate registers + uint32_t block_freq = cache.block_freq = (opoffs & 8) ? ch_block_freq_24(choffs) : ch_block_freq_13(choffs); + + // compute the keycode: block_freq is: + // + // BBBFFFFFFFFFFFF + // ^^^^??? + // + // keycode is not understood, so just guessing it is like OPN: + // the 5-bit keycode uses the top 4 bits plus a magic formula + // for the final bit + uint32_t keycode = bitfield(block_freq, 11, 4) << 1; + + // lowest bit is determined by a mix of next lower FNUM bits + // according to this equation from the YM2608 manual: + // + // (F11 & (F10 | F9 | F8)) | (!F11 & F10 & F9 & F8) + // + // for speed, we just look it up in a 16-bit constant + keycode |= bitfield(0xfe80, bitfield(block_freq, 8, 4)); + + // detune adjustment: the detune values supported by the OPQ are + // a much larger range (6 bits vs 3 bits) compared to any other + // known FM chip; based on experiments, it seems that the extra + // bits provide a bigger detune range rather than finer control, + // so until we get true measurements just assemble a net detune + // value by summing smaller detunes + int32_t detune = int32_t(op_detune(opoffs)) - 0x20; + int32_t abs_detune = std::abs(detune); + int32_t adjust = (abs_detune / 3) * detune_adjustment(3, keycode) + detune_adjustment(abs_detune % 3, keycode); + cache.detune = (detune >= 0) ? adjust : -adjust; + + // multiple value, as an x.1 value (0 means 0.5) + static const uint8_t s_multiple_map[16] = { 1,2,4,6,8,10,12,14,16,18,20,24,30,32,34,36 }; + cache.multiple = s_multiple_map[op_multiple(opoffs)]; + + // phase step, or PHASE_STEP_DYNAMIC if PM is active; this depends on + // block_freq, detune, and multiple, so compute it after we've done those + if (lfo_enable() == 0 || ch_lfo_pm_sens(choffs) == 0) + cache.phase_step = compute_phase_step(choffs, opoffs, cache, 0); + else + cache.phase_step = opdata_cache::PHASE_STEP_DYNAMIC; + + // total level, scaled by 8 + cache.total_level = op_total_level(opoffs) << 3; + + // 4-bit sustain level, but 15 means 31 so effectively 5 bits + cache.eg_sustain = op_sustain_level(opoffs); + cache.eg_sustain |= (cache.eg_sustain + 1) & 0x10; + cache.eg_sustain <<= 5; + + // determine KSR adjustment for enevlope rates + uint32_t ksrval = keycode >> (op_ksr(opoffs) ^ 3); + cache.eg_rate[EG_ATTACK] = effective_rate(op_attack_rate(opoffs) * 2, ksrval); + cache.eg_rate[EG_DECAY] = effective_rate(op_decay_rate(opoffs) * 2, ksrval); + cache.eg_rate[EG_SUSTAIN] = effective_rate(op_sustain_rate(opoffs) * 2, ksrval); + cache.eg_rate[EG_RELEASE] = effective_rate(op_release_rate(opoffs) * 4 + 2, ksrval); + cache.eg_rate[EG_REVERB] = (ch_reverb(choffs) != 0) ? 5*4 : cache.eg_rate[EG_RELEASE]; + cache.eg_shift = 0; +} + + +//------------------------------------------------- +// compute_phase_step - compute the phase step +//------------------------------------------------- + +uint32_t opq_registers::compute_phase_step(uint32_t choffs, uint32_t opoffs, opdata_cache const &cache, int32_t lfo_raw_pm) +{ + // OPN phase calculation has only a single detune parameter + // and uses FNUMs instead of keycodes + + // extract frequency number (low 12 bits of block_freq) + uint32_t fnum = bitfield(cache.block_freq, 0, 12); + + // if there's a non-zero PM sensitivity, compute the adjustment + uint32_t pm_sensitivity = ch_lfo_pm_sens(choffs); + if (pm_sensitivity != 0) + { + // apply the phase adjustment based on the upper 7 bits + // of FNUM and the PM depth parameters + fnum += opn_lfo_pm_phase_adjustment(bitfield(cache.block_freq, 5, 7), pm_sensitivity, lfo_raw_pm); + + // keep fnum to 12 bits + fnum &= 0xfff; + } + + // apply block shift to compute phase step + uint32_t block = bitfield(cache.block_freq, 12, 3); + uint32_t phase_step = (fnum << block) >> 2; + + // apply detune based on the keycode + phase_step += cache.detune; + + // clamp to 17 bits in case detune overflows + // QUESTION: is this specific to the YM2612/3438? + phase_step &= 0x1ffff; + + // apply frequency multiplier (which is cached as an x.1 value) + return (phase_step * cache.multiple) >> 1; +} + + +//------------------------------------------------- +// log_keyon - log a key-on event +//------------------------------------------------- + +std::string opq_registers::log_keyon(uint32_t choffs, uint32_t opoffs) +{ + uint32_t chnum = choffs; + uint32_t opnum = opoffs; + + char buffer[256]; + int end = 0; + + end += snprintf(&buffer[end], sizeof(buffer) - end, "%u.%02u freq=%04X dt=%+2d fb=%u alg=%X mul=%X tl=%02X ksr=%u adsr=%02X/%02X/%02X/%X sl=%X out=%c%c", + chnum, opnum, + (opoffs & 1) ? ch_block_freq_24(choffs) : ch_block_freq_13(choffs), + int32_t(op_detune(opoffs)) - 0x20, + ch_feedback(choffs), + ch_algorithm(choffs), + op_multiple(opoffs), + op_total_level(opoffs), + op_ksr(opoffs), + op_attack_rate(opoffs), + op_decay_rate(opoffs), + op_sustain_rate(opoffs), + op_release_rate(opoffs), + op_sustain_level(opoffs), + ch_output_0(choffs) ? 'L' : '-', + ch_output_1(choffs) ? 'R' : '-'); + + bool am = (lfo_enable() && op_lfo_am_enable(opoffs) && ch_lfo_am_sens(choffs) != 0); + if (am) + end += snprintf(&buffer[end], sizeof(buffer) - end, " am=%u", ch_lfo_am_sens(choffs)); + bool pm = (lfo_enable() && ch_lfo_pm_sens(choffs) != 0); + if (pm) + end += snprintf(&buffer[end], sizeof(buffer) - end, " pm=%u", ch_lfo_pm_sens(choffs)); + if (am || pm) + end += snprintf(&buffer[end], sizeof(buffer) - end, " lfo=%02X", lfo_rate()); + if (ch_reverb(choffs)) + end += snprintf(&buffer[end], sizeof(buffer) - end, " reverb"); + + return buffer; +} + + + +//********************************************************* +// YM3806 +//********************************************************* + +//------------------------------------------------- +// ym3806 - constructor +//------------------------------------------------- + +ym3806::ym3806(ymfm_interface &intf) : + m_fm(intf) +{ +} + + +//------------------------------------------------- +// reset - reset the system +//------------------------------------------------- + +void ym3806::reset() +{ + // reset the engines + m_fm.reset(); +} + + +//------------------------------------------------- +// save_restore - save or restore the data +//------------------------------------------------- + +void ym3806::save_restore(ymfm_saved_state &state) +{ + m_fm.save_restore(state); +} + + +//------------------------------------------------- +// read_status - read the status register +//------------------------------------------------- + +uint8_t ym3806::read_status() +{ + uint8_t result = m_fm.status(); + if (m_fm.intf().ymfm_is_busy()) + result |= fm_engine::STATUS_BUSY; + return result; +} + + +//------------------------------------------------- +// read - handle a read from the device +//------------------------------------------------- + +uint8_t ym3806::read(uint32_t offset) +{ + uint8_t result = 0xff; + switch (offset) + { + case 0: // status port + result = read_status(); + break; + + default: // unknown + debug::log_unexpected_read_write("Unexpected read from YM3806 offset %02X\n", offset); + break; + } +if (TEMPORARY_DEBUG_PRINTS && offset != 0) printf("Read %02X = %02X\n", offset, result); + return result; +} + + +//------------------------------------------------- +// write - handle a write to the register +// interface +//------------------------------------------------- + +void ym3806::write(uint32_t offset, uint8_t data) +{ +if (TEMPORARY_DEBUG_PRINTS && (offset != 3 || data != 0x71)) printf("Write %02X = %02X\n", offset, data); + // write the FM register + m_fm.write(offset, data); +} + + +//------------------------------------------------- +// generate - generate one sample of sound +//------------------------------------------------- + +void ym3806::generate(output_data *output, uint32_t numsamples) +{ + for (uint32_t samp = 0; samp < numsamples; samp++, output++) + { + // clock the system + m_fm.clock(fm_engine::ALL_CHANNELS); + + // update the FM content; YM3806 is full 14-bit with no intermediate clipping + m_fm.output(output->clear(), 0, 32767, fm_engine::ALL_CHANNELS); + + // YM3608 appears to go through a YM3012 DAC, which means we want to apply + // the FP truncation logic to the outputs + output->roundtrip_fp(); + } +} + +} |