/*************************************************************************** tc8830f.c - Toshiba TC8830F, CMOS voice recording/reproducing LSI 1-bit ADM (Adaptive Delta Modulation), similar to TC8801 and T6668. Very preliminary... TODO: - ADM decoder - remaining commands - manual control - chip read - RAM - recording ***************************************************************************/ #include "emu.h" #include "tc8830f.h" // device type definition const device_type TC8830F = &device_creator; tc8830f_device::tc8830f_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, TC8830F, "TC8830F", tag, owner, clock), device_sound_interface(mconfig, *this) { } void tc8830f_device::device_start() { // create the stream m_stream = machine().sound().stream_alloc(*this, 0, 1, clock() / 0x10, this); m_mem_base = (UINT8 *)device().machine().root_device().memregion(":tc8830f")->base(); m_mem_mask = device().machine().root_device().memregion(":tc8830f")->bytes() - 1; // register for savestates save_item(NAME(m_playing)); save_item(NAME(m_address)); save_item(NAME(m_stop_address)); save_item(NAME(m_bitcount)); save_item(NAME(m_bitrate)); save_item(NAME(m_command)); save_item(NAME(m_cmd_rw)); save_item(NAME(m_phrase)); reset(); } void tc8830f_device::device_post_load() { device_clock_changed(); } void tc8830f_device::device_clock_changed() { int divisor = 0x10 * (4 - (m_bitrate & 3)); m_stream->set_sample_rate(clock() / divisor); } void tc8830f_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples) { for (int i = 0; i < samples; i++) { int mix = 0; if (m_playing) { // get bit int bit = m_mem_base[m_address] >> m_bitcount & 1; m_bitcount = (m_bitcount + 1) & 7; if (m_bitcount == 0) { m_address = (m_address + 1) & m_mem_mask; if (m_address == m_stop_address) m_playing = false; } // compute sample // this is a placeholder until ADM is implemented mix = bit * 0x7fff; } outputs[0][i] = mix; } } void tc8830f_device::reset() { m_stream->update(); m_playing = false; m_address = 0x100; m_bitcount = 0; m_cmd_rw = 0; // in cpu control, enter play mode and reset bitrate write_p(1); write_p(6); write_p(0); } void tc8830f_device::write_p(UINT8 data) { m_stream->update(); data &= 0xf; if (m_cmd_rw == 0) { // select command m_command = data; switch (m_command) { // immediate commands case 0x1: break; case 0x2: m_playing = true; break; case 0x3: m_playing = false; break; // multi-nibble commands case 0x4: case 0x5: case 0x6: case 0x7: m_cmd_rw = 1; break; case 0x8: case 0x9: case 0xa: case 0xb: logerror("tc8830f: Unemulated command %X\n", m_command); break; default: logerror("tc8830f: Invalid command %X\n", m_command); break; } } else { // write command switch (m_command) { case 0x4: // ADLD1: set address counter m_address = (m_address & ~(0xf << (m_cmd_rw*4))) | (data << (m_cmd_rw*4)); if (m_cmd_rw == 5) { m_address &= m_mem_mask; m_bitcount = 0; m_cmd_rw = -1; } break; case 0x5: // ADLD2: set address stop m_stop_address = (m_stop_address & ~(0xf << (m_cmd_rw*4))) | (data << (m_cmd_rw*4)); if (m_cmd_rw == 5) { m_stop_address &= m_mem_mask; m_cmd_rw = -1; } break; case 0x6: // CNDT: d0-d1: bitrate, d2: enable overflow m_bitrate = data & 3; device_clock_changed(); m_cmd_rw = -1; break; case 0x7: // LABEL: set phrase if (m_cmd_rw == 1) { m_phrase = (m_phrase & 0x30) | data; } else { m_phrase = (m_phrase & 0x0f) | (data << 4 & 0x30); // update addresses and start UINT8 offs = m_phrase * 4; m_address = (m_mem_base[offs] | m_mem_base[offs|1]<<8 | m_mem_base[offs|2]<<16) & m_mem_mask; offs += 4; m_stop_address = (m_mem_base[offs] | m_mem_base[offs|1]<<8 | m_mem_base[offs|2]<<16) & m_mem_mask; m_bitcount = 0; m_playing = true; m_cmd_rw = -1; } break; default: m_cmd_rw = -1; break; } m_cmd_rw++; } }