// license:BSD-3-Clause // copyright-holders:Valley Bell // register write: // 00/01 - ?? // 02/03 - ROM bank (bits 10-13) / loop mode (bits 14-15) // 04/05 - frequency (2.14 fixed point, 0x4000 = 32000 Hz) // 06/07 - volume // 08/09 - sample start address, fraction (2.14 fixed point, i.e. 1 byte = 0x4000) // 0A/0B - sample start address (high word, i.e. address bits 2..17) // 0C/0D - sample end address (high word) // 0E/0F - sample loop address (high word) // 10/12 - ?? (sometimes value 1F is written) // 11/13/15/17 - voice enable mask (11 = least significant 8 bits, 17 = most significant 8 bits) // 19/1B/1D - ?? (written at init time) // 1A - ?? // 1F - voice select // // register read: // 01 - last sample data (used by main CPU to read sample table from PCM ROM) // 02/03 - ?? (read after writing to 10/12) #include "emu.h" #include "roland_lp.h" DEFINE_DEVICE_TYPE(MB87419_MB87420, mb87419_mb87420_device, "mb87419_mb87420", "Roland LP MB87419/MB87420 PCM") mb87419_mb87420_device::mb87419_mb87420_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, MB87419_MB87420, tag, owner, clock) , device_sound_interface(mconfig, *this) , device_rom_interface(mconfig, *this) , m_int_callback(*this) , m_clock(0) , m_rate(0) , m_stream(nullptr) , m_sel_chn(0) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void mb87419_mb87420_device::device_start() { m_clock = clock() / 2; m_rate = m_clock / 512; // usually 32 KHz m_stream = stream_alloc(0, 2, m_rate); logerror("Roland PCM: Clock %u, Rate %u\n", m_clock, m_rate); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void mb87419_mb87420_device::device_reset() { m_int_callback(CLEAR_LINE); } //------------------------------------------------- // rom_bank_pre_change - refresh the stream if the // ROM banking changes //------------------------------------------------- void mb87419_mb87420_device::rom_bank_pre_change() { // unused right now m_stream->update(); } u8 mb87419_mb87420_device::read(offs_t offset) { // Note: only offset 0x01 is verified, the rest is probably all wrong if (offset != 0x01) logerror("Reading Reg %02X\n", offset); if (offset < 0x10) { pcm_channel& chn = m_chns[m_sel_chn]; switch(offset) { case 0x00: return (chn.mode >> 0) & 0xFF; case 0x01: m_stream->update(); { offs_t addr = (chn.addr >> 14) | ((chn.bank & 0x3C00) << 8); return read_byte(addr); // return sample data } case 0x02: // ROM bank LSB return (chn.bank >> 0) & 0xFF; case 0x03: // ROM bank MSB return (chn.bank >> 8) & 0xFF; case 0x04: // sample step LSB return (chn.step >> 0) & 0xFF; case 0x05: // sample step LSB return (chn.step >> 8) & 0xFF; case 0x06: // volume LSB return (chn.volume >> 0) & 0xFF; case 0x07: // volume MSB return (chn.volume >> 8) & 0xFF; case 0x08: // current address, fraction LSB return (chn.start >> 0) & 0xFF; case 0x09: // current address, fraction MSB return (chn.start >> 8) & 0xFF; case 0x0A: // current address LSB return (chn.start >> 16) & 0xFF; case 0x0B: // current address MSB return (chn.start >> 24) & 0xFF; case 0x0C: // sample end address LSB return (chn.end >> 0) & 0xFF; case 0x0D: // sample end address MSB return (chn.end >> 8) & 0xFF; case 0x0E: // sample loop address LSB return (chn.loop >> 0) & 0xFF; case 0x0F: // sample loop address MSB return (chn.loop >> 8) & 0xFF; } } else { switch(offset) { case 0x11: case 0x13: case 0x15: case 0x17: m_stream->update(); { uint8_t basechn = ((offset >> 1) & 0x03) * 8; uint8_t result = 0x00; for (uint8_t ch_id = 0; ch_id < 8; ch_id ++) result |= (m_chns[basechn + ch_id].enable << ch_id); return result; } break; case 0x1F: return m_sel_chn; } } return 0x00; } void mb87419_mb87420_device::write(offs_t offset, u8 data) { logerror("Reg %02X = %02X\n", offset, data); if (offset < 0x10) { pcm_channel& chn = m_chns[m_sel_chn]; switch(offset) { case 0x00: chn.mode = (chn.mode & 0xFF00) | (data << 0); break; case 0x01: chn.mode = (chn.mode & 0x00FF) | (data << 8); break; case 0x02: // ROM bank LSB chn.bank = (chn.bank & 0xFF00) | (data << 0); break; case 0x03: // ROM bank MSB / loop mode chn.bank = (chn.bank & 0x00FF) | (data << 8); break; case 0x04: // sample step LSB chn.step = (chn.step & 0xFF00) | (data << 0); break; case 0x05: // sample step LSB chn.step = (chn.step & 0x00FF) | (data << 8); break; case 0x06: // volume LSB chn.volume = (chn.volume & 0xFF00) | (data << 0); break; case 0x07: // volume MSB chn.volume = (chn.volume & 0x00FF) | (data << 8); break; case 0x08: // current address, fraction LSB chn.start = (chn.start & 0xFFFFFF00) | (data << 0); if (chn.enable) logerror("Roland PCM, channel %u: changing start address while playing!\n", m_sel_chn); break; case 0x09: // current address, fraction MSB chn.start = (chn.start & 0xFFFF00FF) | (data << 8); if (chn.enable) logerror("Roland PCM, channel %u: changing start address while playing!\n", m_sel_chn); break; case 0x0A: // current address LSB chn.start = (chn.start & 0xFF00FFFF) | (data << 16); if (chn.enable) logerror("Roland PCM, channel %u: changing start address while playing!\n", m_sel_chn); break; case 0x0B: // current address MSB chn.start = (chn.start & 0x00FFFFFF) | (data << 24); if (chn.enable) logerror("Roland PCM, channel %u: changing start address while playing!\n", m_sel_chn); break; case 0x0C: // sample end address, LSB chn.end = (chn.end & 0xFF00) | (data << 0); break; case 0x0D: // sample end address MSB chn.end = (chn.end & 0x00FF) | (data << 8); break; case 0x0E: // sample loop address LSB chn.loop = (chn.loop & 0xFF00) | (data << 0); break; case 0x0F: // sample loop address MSB chn.loop = (chn.loop & 0x00FF) | (data << 8); break; } } else { switch(offset) { case 0x11: case 0x13: case 0x15: case 0x17: { uint8_t basechn = ((offset >> 1) & 0x03) * 8; for (uint8_t ch_id = 0; ch_id < 8; ch_id ++) { pcm_channel& chn = m_chns[basechn + ch_id]; bool play = static_cast((data >> ch_id) & 1); if (play && ! chn.enable) { chn.addr = chn.start; offs_t addr = (chn.addr >> 14) | ((chn.bank & 0x3C00) << 8); chn.smpl_cur = 0; chn.smpl_nxt = decode_sample((int8_t)read_byte(addr)); chn.play_dir = +1; logerror("Starting channel %u, bank 0x%04X, addr 0x%05X.%03X\n", basechn + ch_id, chn.bank, chn.start >> 14, (chn.start & 0x3FFF) << 2); logerror("Smpl End Ofs: 0x%04X, Loop Ofs 0x%04X, Step 0x%04X, Volume %04X\n", chn.end << 2, chn.loop << 2, chn.step, chn.volume); } chn.enable = play; } } break; case 0x1F: m_sel_chn = data & 0x1F; break; default: logerror("Writing unknown reg %02X = %02X\n", offset, data); break; } } } //------------------------------------------------- // sound_stream_update - handle a stream update //------------------------------------------------- void mb87419_mb87420_device::sound_stream_update(sound_stream &stream, std::vector const &inputs, std::vector &outputs) { outputs[0].fill(0); outputs[1].fill(0); for (auto& chn : m_chns) { if (! chn.enable || chn.play_dir == 0) continue; for (int smpl = 0; smpl < outputs[0].samples(); smpl ++) { s32 smp_data; if (chn.play_dir > 0) smp_data = sample_interpolate(chn.smpl_cur, chn.smpl_nxt, chn.addr & 0x3FFF); else smp_data = sample_interpolate(chn.smpl_nxt, chn.smpl_cur, chn.addr & 0x3FFF); smp_data = smp_data * chn.volume; outputs[0].add_int(smpl, smp_data, 32768 << 14); // >>14 results in a good overall volume outputs[1].add_int(smpl, smp_data, 32768 << 14); uint32_t old_addr = chn.addr; if (chn.play_dir > 0) chn.addr += chn.step; else if (chn.play_dir < 0) chn.addr -= chn.step; // Note: The sample data is read after incrementing the address, but before handling loop points. // Reading the sample data after loop point handling breaks the test mode square wave. // (Sample 0xA7 on the CM-32P.) if ((chn.addr >> 14) != (old_addr >> 14)) { offs_t addr = (chn.addr >> 14) | ((chn.bank & 0x3C00) << 8); //logerror("Chn %u: sample addr 0x%05X.%03X\n", &chn - &m_chns[0], chn.addr >> 14, (chn.addr & 0x3FFF) << 2); chn.smpl_cur = chn.smpl_nxt; chn.smpl_nxt += decode_sample((int8_t)read_byte(addr)); // This was verified to be independent from play_dir. // until the decoding is fixed, we prevent overflow bugs (due to DC offsets when looping) this way chn.smpl_nxt = std::clamp(chn.smpl_nxt, -0x7FF, +0x7FF); } bool reachedEnd = false; if (chn.play_dir > 0) { // This works well with the test mode sine/square wave samples. if ((chn.addr >> 16) >= chn.end) reachedEnd = true; } else if (chn.play_dir < 0) { if ((chn.addr >> 16) < chn.loop) reachedEnd = true; } if (reachedEnd) { offs_t oldAddr = chn.addr; logerror("Chn %u: Sample End at addr 0x%05X.%03X. (Dir %d, Loop Mode %u)\n", &chn - &m_chns[0], chn.addr >> 14, (chn.addr & 0x3FFF) << 2, chn.play_dir, chn.bank >> 14); switch(chn.bank >> 14) { case 0: // normal loop chn.addr = chn.addr + ((chn.loop - chn.end) << 16); logerror("addr 0x%05X.%03X -> addr 0x%05X.%03X\n", oldAddr >> 14, (oldAddr & 0x3FFF) << 2, chn.addr >> 14, (chn.addr & 0x3FFF) << 2); break; case 1: // no loop case 3: // invalid, assume "no loop" chn.play_dir = 0; break; case 2: // ping-pong // CM-32P samples with ping-pong loop mode: // 0x00 (low piano note), 0x58..0x67, 0x69..0x6C (choir/strings), 0x9F..0xA4 (brass) // Note: These formulae are probably incorrect, as they cause some DC offset in most samples. // Reference sample rate for C5 @ Sample 9F: 34290 Hz. if (chn.play_dir > 0) chn.addr = (chn.end << 16) - chn.addr + (chn.end << 16); else if (chn.play_dir < 0) chn.addr = (chn.loop << 16) - chn.addr + (chn.loop << 16); chn.play_dir = -chn.play_dir; break; } if (chn.play_dir == 0) break; } } } return; } int16_t mb87419_mb87420_device::decode_sample(int8_t data) { int16_t val; int16_t sign; uint8_t shift; int16_t result; if (data < 0) { sign = -1; val = -data; } else { sign = +1; val = data; } // thanks to Sarayan for figuring out the decoding formula shift = val >> 4; val &= 0x0F; if (! shift) result = val; else result = (0x10 + val) << (shift - 1); return result * sign; } int16_t mb87419_mb87420_device::sample_interpolate(int16_t smp1, int16_t smp2, uint16_t frac) { int32_t smpfrac0 = (int32_t)smp1 * (0x4000 - frac); int32_t smpfrac1 = (int32_t)smp2 * frac; return (int16_t)((smpfrac0 + smpfrac1) >> 14); }