From 77320314042c3a7d41ddd2c10c40a1780d676157 Mon Sep 17 00:00:00 2001 From: tildearrow Date: Wed, 14 Dec 2022 17:07:46 -0500 Subject: [PATCH] update ymfm --- src/engine/platform/sound/ymfm/ymfm.h | 81 +++++++++++++ src/engine/platform/sound/ymfm/ymfm_adpcm.cpp | 107 +++++++++++------- src/engine/platform/sound/ymfm/ymfm_adpcm.h | 8 +- src/engine/platform/sound/ymfm/ymfm_fm.h | 19 +++- src/engine/platform/sound/ymfm/ymfm_fm.ipp | 73 +++++++----- src/engine/platform/sound/ymfm/ymfm_opm.h | 2 +- src/engine/platform/sound/ymfm/ymfm_opn.cpp | 25 +++- src/engine/platform/sound/ymfm/ymfm_opn.h | 2 +- src/engine/platform/sound/ymfm/ymfm_ssg.cpp | 13 +-- src/engine/platform/sound/ymfm/ymfm_ssg.h | 4 +- 10 files changed, 237 insertions(+), 97 deletions(-) diff --git a/src/engine/platform/sound/ymfm/ymfm.h b/src/engine/platform/sound/ymfm/ymfm.h index 7b98f849..47ff9007 100644 --- a/src/engine/platform/sound/ymfm/ymfm.h +++ b/src/engine/platform/sound/ymfm/ymfm.h @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -325,6 +326,86 @@ struct ymfm_output }; +// ======================> ymfm_wavfile + +// this class is a debugging helper that accumulates data and writes it to wav files +template +class ymfm_wavfile +{ +public: + // construction + ymfm_wavfile(uint32_t samplerate = 44100) : + m_samplerate(samplerate) + { + } + + // configuration + ymfm_wavfile &set_index(uint32_t index) { m_index = index; return *this; } + ymfm_wavfile &set_samplerate(uint32_t samplerate) { m_samplerate = samplerate; return *this; } + + // destruction + ~ymfm_wavfile() + { + if (!m_buffer.empty()) + { + // create file + char name[20]; + sprintf(name, "wavlog-%02d.wav", m_index); + FILE *out = fopen(name, "wb"); + + // make the wav file header + uint8_t header[44]; + memcpy(&header[0], "RIFF", 4); + *(uint32_t *)&header[4] = m_buffer.size() * 2 + 44 - 8; + memcpy(&header[8], "WAVE", 4); + memcpy(&header[12], "fmt ", 4); + *(uint32_t *)&header[16] = 16; + *(uint16_t *)&header[20] = 1; + *(uint16_t *)&header[22] = Channels; + *(uint32_t *)&header[24] = m_samplerate; + *(uint32_t *)&header[28] = m_samplerate * 2 * Channels; + *(uint16_t *)&header[32] = 2 * Channels; + *(uint16_t *)&header[34] = 16; + memcpy(&header[36], "data", 4); + *(uint32_t *)&header[40] = m_buffer.size() * 2 + 44 - 44; + + // write header then data + fwrite(&header[0], 1, sizeof(header), out); + fwrite(&m_buffer[0], 2, m_buffer.size(), out); + fclose(out); + } + } + + // add data to the file + template + void add(ymfm_output output) + { + int16_t sum[Channels] = { 0 }; + for (int index = 0; index < Outputs; index++) + sum[index % Channels] += output.data[index]; + for (int index = 0; index < Channels; index++) + m_buffer.push_back(sum[index]); + } + + // add data to the file, using a reference + template + void add(ymfm_output output, ymfm_output const &ref) + { + int16_t sum[Channels] = { 0 }; + for (int index = 0; index < Outputs; index++) + sum[index % Channels] += output.data[index] - ref.data[index]; + for (int index = 0; index < Channels; index++) + m_buffer.push_back(sum[index]); + } + +private: + // internal state + uint32_t m_index; + uint32_t m_samplerate; + std::vector m_buffer; +}; + + // ======================> ymfm_saved_state // this class contains a managed vector of bytes that is used to save and diff --git a/src/engine/platform/sound/ymfm/ymfm_adpcm.cpp b/src/engine/platform/sound/ymfm/ymfm_adpcm.cpp index 76839e78..6d7eb710 100644 --- a/src/engine/platform/sound/ymfm/ymfm_adpcm.cpp +++ b/src/engine/platform/sound/ymfm/ymfm_adpcm.cpp @@ -465,48 +465,60 @@ void adpcm_b_channel::clock() if (position < 0x10000) return; - // if playing from RAM/ROM, check the end address and process - if (m_regs.external()) + // if we're about to process nibble 0, fetch sample + if (m_curnibble == 0) { - // wrap at the limit address - if (at_limit()) - m_curaddress = 0; - - // handle the sample end, either repeating or stopping - if (at_end()) - { - // if repeating, go back to the start - if (m_regs.repeat()) - load_start(); - - // otherwise, done; set the EOS bit and return - else - { - m_accumulator = 0; - m_prev_accum = 0; - m_status = (m_status & ~STATUS_PLAYING) | STATUS_EOS; - debug::log_keyon("%s\n", "ADPCM EOS"); - return; - } - } - - // if we're about to process nibble 0, fetch and increment - if (m_curnibble == 0) - { - m_curbyte = m_owner.intf().ymfm_external_read(ACCESS_ADPCM_B, m_curaddress++); - m_curaddress &= 0xffffff; - } + // playing from RAM/ROM + if (m_regs.external()) + m_curbyte = m_owner.intf().ymfm_external_read(ACCESS_ADPCM_B, m_curaddress); } // extract the nibble from our current byte uint8_t data = uint8_t(m_curbyte << (4 * m_curnibble)) >> 4; m_curnibble ^= 1; - // if CPU-driven and we just processed the last nibble, copy the next byte and request more - if (m_curnibble == 0 && !m_regs.external()) + // we just processed the last nibble + if (m_curnibble == 0) { - m_curbyte = m_regs.cpudata(); - m_status |= STATUS_BRDY; + // if playing from RAM/ROM, check the end/limit address or advance + if (m_regs.external()) + { + // handle the sample end, either repeating or stopping + if (at_end()) + { + // if repeating, go back to the start + if (m_regs.repeat()) + load_start(); + + // otherwise, done; set the EOS bit + else + { + m_accumulator = 0; + m_prev_accum = 0; + m_status = (m_status & ~STATUS_PLAYING) | STATUS_EOS; + debug::log_keyon("%s\n", "ADPCM EOS"); + return; + } + } + + // wrap at the limit address + else if (at_limit()) + m_curaddress = 0; + + // otherwise, advance the current address + else + { + m_curaddress++; + m_curaddress &= 0xffffff; + } + } + + // if CPU-driven, copy the next byte and request more + else + { + m_curbyte = m_regs.cpudata(); + m_status |= STATUS_BRDY; + } } // remember previous value for interpolation @@ -574,18 +586,27 @@ uint8_t adpcm_b_channel::read(uint32_t regnum) m_dummy_read--; } - // did we hit the end? if so, signal EOS - if (at_end()) - { - m_status = STATUS_EOS | STATUS_BRDY; - debug::log_keyon("%s\n", "ADPCM EOS"); - } - - // otherwise, write the data and signal ready + // read the data else { + // read from outside of the chip result = m_owner.intf().ymfm_external_read(ACCESS_ADPCM_B, m_curaddress++); - m_status = STATUS_BRDY; + + // did we hit the end? if so, signal EOS + if (at_end()) + { + m_status = STATUS_EOS | STATUS_BRDY; + debug::log_keyon("%s\n", "ADPCM EOS"); + } + else + { + // signal ready + m_status = STATUS_BRDY; + } + + // wrap at the limit address + if (at_limit()) + m_curaddress = 0; } } return result; diff --git a/src/engine/platform/sound/ymfm/ymfm_adpcm.h b/src/engine/platform/sound/ymfm/ymfm_adpcm.h index 58bee8a2..f80e6ab9 100644 --- a/src/engine/platform/sound/ymfm/ymfm_adpcm.h +++ b/src/engine/platform/sound/ymfm/ymfm_adpcm.h @@ -351,11 +351,11 @@ private: // load the start address void load_start(); - // limit checker - bool at_limit() const { return (m_curaddress >> address_shift()) >= m_regs.limit(); } + // limit checker; stops at the last byte of the chunk described by address_shift() + bool at_limit() const { return (m_curaddress == (((m_regs.limit() + 1) << address_shift()) - 1)); } - // end checker - bool at_end() const { return (m_curaddress >> address_shift()) > m_regs.end(); } + // end checker; stops at the last byte of the chunk described by address_shift() + bool at_end() const { return (m_curaddress == (((m_regs.end() + 1) << address_shift()) - 1)); } // internal state uint32_t const m_address_shift; // address bits shift-left diff --git a/src/engine/platform/sound/ymfm/ymfm_fm.h b/src/engine/platform/sound/ymfm/ymfm_fm.h index 352ac946..df3b486a 100644 --- a/src/engine/platform/sound/ymfm/ymfm_fm.h +++ b/src/engine/platform/sound/ymfm/ymfm_fm.h @@ -33,6 +33,8 @@ #pragma once +#define YMFM_DEBUG_LOG_WAVFILES (0) + namespace ymfm { @@ -162,8 +164,8 @@ template class fm_engine_base; template class fm_operator { - // "quiet" value, used to optimize when we can skip doing working - static constexpr uint32_t EG_QUIET = 0x200; + // "quiet" value, used to optimize when we can skip doing work + static constexpr uint32_t EG_QUIET = 0x380; public: // constructor @@ -206,6 +208,7 @@ public: // simple getters for debugging envelope_state debug_eg_state() const { return m_env_state; } uint16_t debug_eg_attenuation() const { return m_env_attenuation; } + uint8_t debug_ssg_inverted() const { return m_ssg_inverted; } opdata_cache &debug_cache() { return m_cache; } private: @@ -406,7 +409,14 @@ public: void set_clock_prescale(uint32_t prescale) { m_clock_prescale = prescale; } // compute sample rate - uint32_t sample_rate(uint32_t baseclock) const { return baseclock / (m_clock_prescale * OPERATORS); } + uint32_t sample_rate(uint32_t baseclock) const + { +#if (YMFM_DEBUG_LOG_WAVFILES) + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + m_wavfile[chnum].set_samplerate(baseclock / (m_clock_prescale * OPERATORS)); +#endif + return baseclock / (m_clock_prescale * OPERATORS); + } // return the owning device ymfm_interface &intf() const { return m_intf; } @@ -453,6 +463,9 @@ protected: RegisterType m_regs; // register accessor std::unique_ptr> m_channel[CHANNELS]; // channel pointers std::unique_ptr> m_operator[OPERATORS]; // operator pointers +#if (YMFM_DEBUG_LOG_WAVFILES) + mutable ymfm_wavfile<1> m_wavfile[CHANNELS]; // for debugging +#endif }; } diff --git a/src/engine/platform/sound/ymfm/ymfm_fm.ipp b/src/engine/platform/sound/ymfm/ymfm_fm.ipp index d532d7b2..6eab8308 100644 --- a/src/engine/platform/sound/ymfm/ymfm_fm.ipp +++ b/src/engine/platform/sound/ymfm/ymfm_fm.ipp @@ -448,6 +448,8 @@ void fm_operator::clock(uint32_t env_counter, int32_t lfo_raw_pm) // clock the SSG-EG state (OPN/OPNA) if (m_regs.op_ssg_eg_enable(m_opoffs)) clock_ssg_eg_state(); + else + m_ssg_inverted = false; // clock the envelope if on an envelope cycle; env_counter is a x.2 value if (bitfield(env_counter, 0, 2) == 0) @@ -470,15 +472,6 @@ int32_t fm_operator::compute_volume(uint32_t phase, uint32_t am_of // the low 10 bits of phase represents a full 2*PI period over // the full sin wave -#if 0 -// temporary envelope logging -if (m_choffs == 0) -{ - printf(" %c@%02X:%03X", "PADSRV"[m_env_state], m_cache.eg_rate[m_env_state], envelope_attenuation(am_offset)); - if (m_opoffs == 0x18) printf("\n"); -} -#endif - // early out if the envelope is effectively off if (m_env_attenuation > EG_QUIET && m_cache.eg_shift == 0) return 0; @@ -896,6 +889,23 @@ void fm_channel::clock(uint32_t env_counter, int32_t lfo_raw_pm) for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) if (m_op[opnum] != nullptr) m_op[opnum]->clock(env_counter, lfo_raw_pm); + +/* +useful temporary code for envelope debugging +if (m_choffs == 0x101) +{ + for (uint32_t opnum = 0; opnum < array_size(m_op); opnum++) + { + auto &op = *m_op[((opnum & 1) << 1) | ((opnum >> 1) & 1)]; + printf(" %c%03X%c%c ", + "PADSRV"[op.debug_eg_state()], + op.debug_eg_attenuation(), + op.debug_ssg_inverted() ? '-' : '+', + m_regs.op_ssg_eg_enable(op.opoffs()) ? '0' + m_regs.op_ssg_eg_mode(op.opoffs()) : ' '); + } +printf(" -- "); +} +*/ } @@ -943,7 +953,8 @@ void fm_channel::output_2op(output_data &output, uint32_t rshift, } else { - result = op1value + (m_op[1]->compute_volume(m_op[1]->phase(), am_offset) >> rshift); + result = (RegisterType::MODULATOR_DELAY ? m_feedback[1] : op1value) >> rshift; + result += m_op[1]->compute_volume(m_op[1]->phase(), am_offset) >> rshift; int32_t clipmin = -clipmax - 1; result = clamp(result, clipmin, clipmax); } @@ -1180,6 +1191,7 @@ fm_engine_base::fm_engine_base(ymfm_interface &intf) : m_irq_mask(STATUS_TIMERA | STATUS_TIMERB), m_irq_state(0), m_timer_running{0,0}, + m_total_clocks(0), m_active_channels(ALL_CHANNELS), m_modified_channels(ALL_CHANNELS), m_prepare_count(0) @@ -1195,6 +1207,11 @@ fm_engine_base::fm_engine_base(ymfm_interface &intf) : for (uint32_t opnum = 0; opnum < OPERATORS; opnum++) m_operator[opnum] = std::make_unique>(*this, RegisterType::operator_offset(opnum)); +#if (YMFM_DEBUG_LOG_WAVFILES) + for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) + m_wavfile[chnum].set_index(chnum); +#endif + // do the initial operator assignment assign_operators(); } @@ -1305,24 +1322,6 @@ uint32_t fm_engine_base::clock(uint32_t chanmask) if (bitfield(chanmask, chnum)) m_channel[chnum]->clock(m_env_counter, lfo_raw_pm); -#if 0 -//Temporary debugging... -static double curtime = 0; -//for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) -uint32_t chnum = 4; -{ - printf("t=%.4f ch%d: ", curtime, chnum); - for (uint32_t opnum = 0; opnum < 4; opnum++) - { - auto op = debug_channel(chnum)->debug_operator(opnum); - auto eg_state = op->debug_eg_state(); - printf(" %c%03X[%02X]%c ", "PADSRV"[eg_state], op.debug_eg_attenuation(), op.debug_cache().eg_rate[eg_state], m_regs.op_ssg_eg_enable(op.opoffs()) ? '*' : ' '); - } - printf(" -- "); -} -curtime += 1.0 / double(sample_rate(7670454)); -#endif - // return the envelope counter as it is used to clock ADPCM-A return m_env_counter; } @@ -1340,7 +1339,8 @@ void fm_engine_base::output(output_data &output, uint32_t rshift, chanmask &= debug::GLOBAL_FM_CHANNEL_MASK; // mask out inactive channels - chanmask &= m_active_channels; + if (!YMFM_DEBUG_LOG_WAVFILES) + chanmask &= m_active_channels; // handle the rhythm case, where some of the operators are dedicated // to percussion (this is an OPL-specific feature) @@ -1358,6 +1358,9 @@ void fm_engine_base::output(output_data &output, uint32_t rshift, for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) if (bitfield(chanmask, chnum)) { +#if (YMFM_DEBUG_LOG_WAVFILES) + auto reference = output; +#endif if (chnum == 6) m_channel[chnum]->output_rhythm_ch6(output, rshift, clipmax); else if (chnum == 7) @@ -1368,6 +1371,9 @@ void fm_engine_base::output(output_data &output, uint32_t rshift, m_channel[chnum]->output_4op(output, rshift, clipmax); else m_channel[chnum]->output_2op(output, rshift, clipmax); +#if (YMFM_DEBUG_LOG_WAVFILES) + m_wavfile[chnum].add(output, reference); +#endif } } else @@ -1376,10 +1382,16 @@ void fm_engine_base::output(output_data &output, uint32_t rshift, for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) if (bitfield(chanmask, chnum)) { +#if (YMFM_DEBUG_LOG_WAVFILES) + auto reference = output; +#endif if (m_channel[chnum]->is4op()) m_channel[chnum]->output_4op(output, rshift, clipmax); else m_channel[chnum]->output_2op(output, rshift, clipmax); +#if (YMFM_DEBUG_LOG_WAVFILES) + m_wavfile[chnum].add(output, reference); +#endif } } } @@ -1508,7 +1520,10 @@ void fm_engine_base::engine_timer_expired(uint32_t tnum) if (tnum == 0 && m_regs.csm()) for (uint32_t chnum = 0; chnum < CHANNELS; chnum++) if (bitfield(RegisterType::CSM_TRIGGER_MASK, chnum)) + { m_channel[chnum]->keyonoff(1, KEYON_CSM, chnum); + m_modified_channels |= 1 << chnum; + } // reset m_timer_running[tnum] = false; diff --git a/src/engine/platform/sound/ymfm/ymfm_opm.h b/src/engine/platform/sound/ymfm/ymfm_opm.h index 830b195e..2034b5f4 100644 --- a/src/engine/platform/sound/ymfm/ymfm_opm.h +++ b/src/engine/platform/sound/ymfm/ymfm_opm.h @@ -174,7 +174,7 @@ public: // system-wide registers uint32_t test() const { return byte(0x01, 0, 8); } uint32_t lfo_reset() const { return byte(0x01, 1, 1); } - uint32_t noise_frequency() const { return byte(0x0f, 0, 5); } + uint32_t noise_frequency() const { return byte(0x0f, 0, 5) ^ 0x1f; } uint32_t noise_enable() const { return byte(0x0f, 7, 1); } uint32_t timer_a_value() const { return word(0x10, 0, 8, 0x11, 0, 2); } uint32_t timer_b_value() const { return byte(0x12, 0, 8); } diff --git a/src/engine/platform/sound/ymfm/ymfm_opn.cpp b/src/engine/platform/sound/ymfm/ymfm_opn.cpp index 00ac2cf6..053ad977 100644 --- a/src/engine/platform/sound/ymfm/ymfm_opn.cpp +++ b/src/engine/platform/sound/ymfm/ymfm_opn.cpp @@ -146,7 +146,10 @@ bool opn_registers_base::write(uint16_t index, uint8_t data, uint32_t &c // borrow unused registers 0xb8-bf/0x1b8-bf as temporary holding locations if ((index & 0xf0) == 0xa0) { - uint32_t latchindex = 0xb8 | (bitfield(index, 3) << 2) | bitfield(index, 0, 2); + if (bitfield(index, 0, 2) == 3) + return false; + + uint32_t latchindex = 0xb8 | bitfield(index, 3); if (IsOpnA) latchindex |= index & 0x100; @@ -157,9 +160,16 @@ bool opn_registers_base::write(uint16_t index, uint8_t data, uint32_t &c // writes to the lower half only commit if the latch is there else if (bitfield(m_regdata[latchindex], 7)) { + m_regdata[index] = data; m_regdata[index | 4] = m_regdata[latchindex] & 0x3f; m_regdata[latchindex] = 0; } + return false; + } + else if ((index & 0xf8) == 0xb8) + { + // registers 0xb8-0xbf are used internally + return false; } // everything else is normal @@ -195,7 +205,12 @@ int32_t opn_registers_base::clock_noise_and_lfo() if (!IsOpnA || !lfo_enable()) { m_lfo_counter = 0; - m_lfo_am = 0; + + // special case: if LFO is disabled on OPNA, it basically just keeps the counter + // at 0; since position 0 gives an AM value of 0x3f, it is important to reflect + // that here; for example, MegaDrive Venom plays some notes with LFO globally + // disabled but enabling LFO on the operators, and it expects this added attenutation + m_lfo_am = IsOpnA ? 0x3f : 0x00; return 0; } @@ -417,10 +432,10 @@ std::string opn_registers_base::log_keyon(uint32_t choffs, uint32_t opof ch_output_1(choffs) ? 'R' : '-'); if (op_ssg_eg_enable(opoffs)) end += sprintf(end, " ssg=%X", op_ssg_eg_mode(opoffs)); - bool am = (lfo_enable() && op_lfo_am_enable(opoffs) && ch_lfo_am_sens(choffs) != 0); + bool am = (op_lfo_am_enable(opoffs) && ch_lfo_am_sens(choffs) != 0); if (am) end += sprintf(end, " am=%u", ch_lfo_am_sens(choffs)); - bool pm = (lfo_enable() && ch_lfo_pm_sens(choffs) != 0); + bool pm = (ch_lfo_pm_sens(choffs) != 0); if (pm) end += sprintf(end, " pm=%u", ch_lfo_pm_sens(choffs)); if (am || pm) @@ -1094,7 +1109,7 @@ uint8_t ym2608::read_status_hi() uint8_t ym2608::read_data_hi() { uint8_t result = 0; - if (m_address < 0x10) + if ((m_address & 0xff) < 0x10) { // 00-0F: Read from ADPCM-B result = m_adpcm_b.read(m_address & 0x0f); diff --git a/src/engine/platform/sound/ymfm/ymfm_opn.h b/src/engine/platform/sound/ymfm/ymfm_opn.h index 00fd61ad..2a9b92d5 100644 --- a/src/engine/platform/sound/ymfm/ymfm_opn.h +++ b/src/engine/platform/sound/ymfm/ymfm_opn.h @@ -784,7 +784,7 @@ public: protected: // simulate the DAC discontinuity - int32_t dac_discontinuity(int32_t value) const { return (value < 0) ? (value - 2) : (value + 3); } + int32_t dac_discontinuity(int32_t value) const { return (value < 0) ? (value - 3) : (value + 4); } // internal state uint16_t m_address; // address register diff --git a/src/engine/platform/sound/ymfm/ymfm_ssg.cpp b/src/engine/platform/sound/ymfm/ymfm_ssg.cpp index 5a9a9d43..77a62563 100644 --- a/src/engine/platform/sound/ymfm/ymfm_ssg.cpp +++ b/src/engine/platform/sound/ymfm/ymfm_ssg.cpp @@ -201,19 +201,14 @@ void ssg_engine::output(output_data &output) for (int chan = 0; chan < 3; chan++) { // noise depends on the noise state, which is the LSB of m_noise_state - uint32_t noise_on = m_regs.ch_noise_enable(chan) & m_noise_state; + uint32_t noise_on = m_regs.ch_noise_enable_n(chan) | m_noise_state; // tone depends on the current tone state - uint32_t tone_on = m_regs.ch_tone_enable(chan) & m_tone_state[chan]; + uint32_t tone_on = m_regs.ch_tone_enable_n(chan) | m_tone_state[chan]; - // if envelope is enabled but tone and noise aren't, use the envelope - // volume + // if neither tone nor noise enabled, return 0 uint32_t volume; - if (m_regs.ch_envelope_enable(chan) && !m_regs.ch_noise_enable(chan) && !m_regs.ch_tone_enable(chan)) - volume = envelope_volume; - - // if neither tone nor noise enabled, return 0 - else if ((noise_on | tone_on) == 0) + if ((noise_on & tone_on) == 0) volume = 0; // if the envelope is enabled, use its amplitude diff --git a/src/engine/platform/sound/ymfm/ymfm_ssg.h b/src/engine/platform/sound/ymfm/ymfm_ssg.h index 55e748d6..df974fe4 100644 --- a/src/engine/platform/sound/ymfm/ymfm_ssg.h +++ b/src/engine/platform/sound/ymfm/ymfm_ssg.h @@ -130,8 +130,8 @@ public: uint32_t io_b_data() const { return m_regdata[0x0f]; } // per-channel registers - uint32_t ch_noise_enable(uint32_t choffs) const { return bitfield(~m_regdata[0x07], 3 + choffs); } - uint32_t ch_tone_enable(uint32_t choffs) const { return bitfield(~m_regdata[0x07], 0 + choffs); } + uint32_t ch_noise_enable_n(uint32_t choffs) const { return bitfield(m_regdata[0x07], 3 + choffs); } + uint32_t ch_tone_enable_n(uint32_t choffs) const { return bitfield(m_regdata[0x07], 0 + choffs); } uint32_t ch_tone_period(uint32_t choffs) const { return m_regdata[0x00 + 2 * choffs] | (bitfield(m_regdata[0x01 + 2 * choffs], 0, 4) << 8); } uint32_t ch_envelope_enable(uint32_t choffs) const { return bitfield(m_regdata[0x08 + choffs], 4); } uint32_t ch_amplitude(uint32_t choffs) const { return bitfield(m_regdata[0x08 + choffs], 0, 4); }