// license:BSD-3-Clause // copyright-holders:Aaron Giles /*************************************************************************** Bally/Sente 6VB audio board emulation This serial audio board appears to be based on the Sequential Circuits Six-Trak synthesizer. The later revision of this board replaces the 8253-5 PIT and much associated logic with a ST1001 custom gate array. **************************************************************************** Memory map **************************************************************************** ======================================================================== Z80 CPU ======================================================================== 0000-1FFF R xxxxxxxx Program ROM 2000-3FFF R/W xxxxxxxx Option RAM/ROM (assumed to be RAM for now) 4000-5FFF R/W xxxxxxxx Program RAM 6000-6001 W xxxxxxxx 6850 UART output (to main board) E000-E001 R xxxxxxxx 6850 UART input (from main board) ======================================================================== 0000-0003 R/W xxxxxxxx 8253 counter chip I/O 0008 R ------xx Counter state R ------x- State of counter #0 OUT signal (active high) R -------x State of flip-flop feeding counter #0 (active low) 0008 W --xxxxxx Counter control W --x----- NMI enable (1=enabled, 0=disabled/clear) W ---x---- CLEAR on flip-flop feeding counter #0 (active low) W ----x--- Input of flip-flop feeding counter #0 W -----x-- PRESET on flip-flop feeding counter #0 (active low) W ------x- GATE signal for counter #0 (active high) W -------x Audio enable 000A W --xxxxxx DAC data latch (upper 6 bits) 000B W xxxxxx-- DAC data latch (lower 6 bits) 000C W -----xxx CEM3394 register select 000E W --xxxxxx CEM3394 chip enable (active high) W --x----- CEM3394 chip 0 enable W ---x---- CEM3394 chip 1 enable W ----x--- CEM3394 chip 2 enable W -----x-- CEM3394 chip 3 enable W ------x- CEM3394 chip 4 enable W -------x CEM3394 chip 5 enable ======================================================================== Interrupts: INT generated by counter #2 OUT signal on 8253 NMI generated by 6850 UART ======================================================================== ***************************************************************************/ #include "emu.h" #include "audio/sente6vb.h" #include "cpu/z80/z80.h" #include "machine/clock.h" #include "speaker.h" #define LOG_CEM_WRITES 0 DEFINE_DEVICE_TYPE(SENTE6VB, sente6vb_device, "sente6vb", "Bally Sente 6VB Audio Board") /************************************* * * Sound CPU memory handlers * *************************************/ void sente6vb_device::mem_map(address_map &map) { map(0x0000, 0x1fff).rom().region("audiocpu", 0); map(0x2000, 0x5fff).ram(); map(0x6000, 0x6001).mirror(0x1ffe).w(m_uart, FUNC(acia6850_device::write)); map(0xe000, 0xe001).mirror(0x1ffe).r(m_uart, FUNC(acia6850_device::read)); } void sente6vb_device::io_map(address_map &map) { map.global_mask(0xff); map(0x00, 0x03).rw(m_pit, FUNC(pit8253_device::read), FUNC(pit8253_device::write)); map(0x08, 0x0f).r(FUNC(sente6vb_device::counter_state_r)); map(0x08, 0x09).w(FUNC(sente6vb_device::counter_control_w)); map(0x0a, 0x0b).w(FUNC(sente6vb_device::dac_data_w)); map(0x0c, 0x0d).w(FUNC(sente6vb_device::register_addr_w)); map(0x0e, 0x0f).w(FUNC(sente6vb_device::chip_select_w)); } /************************************* * * Device configuration * *************************************/ void sente6vb_device::device_add_mconfig(machine_config &config) { Z80(config, m_audiocpu, 8_MHz_XTAL / 2); m_audiocpu->set_addrmap(AS_PROGRAM, &sente6vb_device::mem_map); m_audiocpu->set_addrmap(AS_IO, &sente6vb_device::io_map); ACIA6850(config, m_uart, 0); m_uart->txd_handler().set([this] (int state) { m_send_cb(state); }); m_uart->irq_handler().set([this] (int state) { m_uint = bool(state); }); clock_device &uartclock(CLOCK(config, "uartclock", 8_MHz_XTAL / 16)); // 500 kHz uartclock.signal_handler().set(FUNC(sente6vb_device::uart_clock_w)); uartclock.signal_handler().append(m_uart, FUNC(acia6850_device::write_txc)); uartclock.signal_handler().append(m_uart, FUNC(acia6850_device::write_rxc)); TIMER(config, m_counter_0_timer, 0).configure_generic(FUNC(sente6vb_device::clock_counter_0_ff)); PIT8253(config, m_pit, 0); m_pit->out_handler<0>().set(FUNC(sente6vb_device::counter_0_set_out)); m_pit->out_handler<2>().set_inputline(m_audiocpu, INPUT_LINE_IRQ0); m_pit->set_clk<1>(8_MHz_XTAL / 4); m_pit->set_clk<2>(8_MHz_XTAL / 4); SPEAKER(config, "mono").front_center(); for (auto &cem_device : m_cem_device) { CEM3394(config, cem_device, 0); cem_device->set_vco_zero_freq(431.894); cem_device->set_filter_zero_freq(1300.0); cem_device->add_route(ALL_OUTPUTS, "mono", 0.90); } m_cem_device[0]->set_ext_input_callback(FUNC(sente6vb_device::noise_gen_0)); m_cem_device[1]->set_ext_input_callback(FUNC(sente6vb_device::noise_gen_1)); m_cem_device[2]->set_ext_input_callback(FUNC(sente6vb_device::noise_gen_2)); m_cem_device[3]->set_ext_input_callback(FUNC(sente6vb_device::noise_gen_3)); m_cem_device[4]->set_ext_input_callback(FUNC(sente6vb_device::noise_gen_4)); m_cem_device[5]->set_ext_input_callback(FUNC(sente6vb_device::noise_gen_5)); } /************************************* * * ROM definition * *************************************/ ROM_START( sente6vb ) ROM_REGION( 0x2000, "audiocpu", 0 ) ROM_LOAD( "8002-10 9-25-84.5", 0x0000, 0x2000, CRC(4dd0a525) SHA1(f0c447adc5b67917851a9df978df851247e75c43) ) ROM_END const tiny_rom_entry *sente6vb_device::device_rom_region() const { return ROM_NAME(sente6vb); } /************************************* * * Device initialization * *************************************/ sente6vb_device::sente6vb_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, SENTE6VB, tag, owner, clock) , m_pit(*this, "pit") , m_counter_0_timer(*this, "8253_0_timer") , m_cem_device(*this, "cem%u", 1U) , m_audiocpu(*this, "audiocpu") , m_uart(*this, "uart") , m_send_cb(*this) , m_clock_out_cb(*this) { } void sente6vb_device::device_start() { // create the polynomial tables poly17_init(); m_send_cb.resolve_safe(); m_clock_out_cb.resolve_safe(); m_uart->write_cts(0); m_uart->write_dcd(0); save_item(NAME(m_counter_control)); save_item(NAME(m_counter_0_ff)); save_item(NAME(m_counter_0_out)); save_item(NAME(m_counter_0_timer_active)); save_item(NAME(m_dac_value)); save_item(NAME(m_dac_register)); save_item(NAME(m_chip_select)); save_item(NAME(m_uint)); save_item(NAME(m_noise_position)); } void sente6vb_device::device_reset() { // reset the manual counter 0 clock m_counter_control = 0x00; m_counter_0_ff = false; m_counter_0_out = false; m_counter_0_timer_active = false; m_audiocpu->set_input_line(INPUT_LINE_NMI, CLEAR_LINE); // reset the CEM3394 I/O states m_dac_value = 0; m_dac_register = 0; m_chip_select = 0x3f; // reset the noise generator memset(m_noise_position, 0, sizeof(m_noise_position)); } /************************************* * * MM5837 noise generator * * NOTE: this is stolen straight from * POKEY.c * *************************************/ void sente6vb_device::poly17_init() { uint32_t i, x = 0; uint8_t *p; // allocate memory p = m_poly17; // generate the polynomial for (i = 0; i < POLY17_SIZE; i++) { // store new values *p++ = x & 1; // calculate next bit x = ((x << POLY17_SHL) + (x >> POLY17_SHR) + POLY17_ADD) & POLY17_SIZE; } } inline void sente6vb_device::noise_gen_chip(int chip, int count, short *buffer) { // noise generator runs at 100kHz uint32_t step = (100000 << 14) / cem3394_device::SAMPLE_RATE; uint32_t noise_counter = m_noise_position[chip]; while (count--) { *buffer++ = m_poly17[(noise_counter >> 14) & POLY17_SIZE] << 12; noise_counter += step; } // remember the noise position m_noise_position[chip] = noise_counter; } CEM3394_EXT_INPUT(sente6vb_device::noise_gen_0) { noise_gen_chip(0, count, buffer); } CEM3394_EXT_INPUT(sente6vb_device::noise_gen_1) { noise_gen_chip(1, count, buffer); } CEM3394_EXT_INPUT(sente6vb_device::noise_gen_2) { noise_gen_chip(2, count, buffer); } CEM3394_EXT_INPUT(sente6vb_device::noise_gen_3) { noise_gen_chip(3, count, buffer); } CEM3394_EXT_INPUT(sente6vb_device::noise_gen_4) { noise_gen_chip(4, count, buffer); } CEM3394_EXT_INPUT(sente6vb_device::noise_gen_5) { noise_gen_chip(5, count, buffer); } /************************************* * * 6850 UART communications * *************************************/ WRITE_LINE_MEMBER(sente6vb_device::rec_w) { m_uart->write_rxd(state); } WRITE_LINE_MEMBER(sente6vb_device::uart_clock_w) { if (state && BIT(m_counter_control, 5)) m_audiocpu->set_input_line(INPUT_LINE_NMI, m_uint ? ASSERT_LINE : CLEAR_LINE); m_clock_out_cb(!state); } /************************************* * * Sound CPU counter 0 emulation * *************************************/ WRITE_LINE_MEMBER(sente6vb_device::counter_0_set_out) { // OUT on counter 0 is hooked to the GATE line on counter 1 through an inverter m_pit->write_gate1(!state); // remember the out state m_counter_0_out = state; } WRITE_LINE_MEMBER(sente6vb_device::set_counter_0_ff) { // the flip/flop output is inverted, so if we went high to low, that's a clock m_pit->write_clk0(!state); // remember the new state m_counter_0_ff = state; } TIMER_DEVICE_CALLBACK_MEMBER(sente6vb_device::clock_counter_0_ff) { // clock the D value through the flip-flop set_counter_0_ff(BIT(m_counter_control, 3)); } void sente6vb_device::update_counter_0_timer() { double maxfreq = 0.0; int i; // if there's already a timer, remove it if (m_counter_0_timer_active) m_counter_0_timer->reset(); m_counter_0_timer_active = false; // find the counter with the maximum frequency // this is used to calibrate the timers at startup for (i = 0; i < 6; i++) if (m_cem_device[i]->get_parameter(cem3394_device::FINAL_GAIN) < 10.0) { double tempfreq; // if the filter resonance is high, then they're calibrating the filter frequency if (m_cem_device[i]->get_parameter(cem3394_device::FILTER_RESONANCE) > 0.9) tempfreq = m_cem_device[i]->get_parameter(cem3394_device::FILTER_FREQENCY); // otherwise, they're calibrating the VCO frequency else tempfreq = m_cem_device[i]->get_parameter(cem3394_device::VCO_FREQUENCY); if (tempfreq > maxfreq) maxfreq = tempfreq; } // reprime the timer if (maxfreq > 0.0) { m_counter_0_timer_active = true; m_counter_0_timer->adjust(attotime::from_hz(maxfreq), 0, attotime::from_hz(maxfreq)); } } /************************************* * * Sound CPU counter handlers * *************************************/ READ8_MEMBER(sente6vb_device::counter_state_r) { // bit D0 is the inverse of the flip-flop state int result = !m_counter_0_ff; // bit D1 is the OUT value from counter 0 if (m_counter_0_out) result |= 0x02; return result; } WRITE8_MEMBER(sente6vb_device::counter_control_w) { uint8_t diff_counter_control = m_counter_control ^ data; // set the new global value m_counter_control = data; // bit D0 enables/disables audio if (BIT(diff_counter_control, 0)) { for (auto & elem : m_cem_device) elem->set_output_gain(0, BIT(data, 0) ? 1.0 : 0); } // bit D1 is hooked to counter 0's gate if (BIT(diff_counter_control, 1)) { // if we gate on, start a pulsing timer to clock it if (BIT(data, 1) && !m_counter_0_timer_active) { update_counter_0_timer(); } // if we gate off, remove the timer else if (!BIT(data, 1) && m_counter_0_timer_active) { m_counter_0_timer->reset(); m_counter_0_timer_active = false; } } // set the actual gate m_pit->write_gate0(BIT(data, 1)); // bits D2 and D4 control the clear/reset flags on the flip-flop that feeds counter 0 if (!BIT(data, 4)) set_counter_0_ff(0); else if (!BIT(data, 2)) set_counter_0_ff(1); // bit 5 clears the NMI interrupt if (BIT(diff_counter_control, 5) && !BIT(data, 5)) m_audiocpu->set_input_line(INPUT_LINE_NMI, CLEAR_LINE); } /************************************* * * CEM3394 Interfaces * *************************************/ WRITE8_MEMBER(sente6vb_device::chip_select_w) { static constexpr uint8_t register_map[8] = { cem3394_device::VCO_FREQUENCY, cem3394_device::FINAL_GAIN, cem3394_device::FILTER_RESONANCE, cem3394_device::FILTER_FREQENCY, cem3394_device::MIXER_BALANCE, cem3394_device::MODULATION_AMOUNT, cem3394_device::PULSE_WIDTH, cem3394_device::WAVE_SELECT }; double voltage = (double)m_dac_value * (8.0 / 4096.0) - 4.0; int diffchip = data ^ m_chip_select, i; int reg = register_map[m_dac_register]; // remember the new select value m_chip_select = data; // check all six chip enables for (i = 0; i < 6; i++) if ((diffchip & (1 << i)) && (data & (1 << i))) { #if LOG_CEM_WRITES double temp = 0; // remember the previous value temp = #endif m_cem_device[i]->get_parameter(reg); // set the voltage m_cem_device[i]->set_voltage(reg, voltage); // only log changes #if LOG_CEM_WRITES if (temp != m_cem_device[i]->get_parameter(reg)) { static const char *const names[] = { "VCO_FREQUENCY", "FINAL_GAIN", "FILTER_RESONANCE", "FILTER_FREQENCY", "MIXER_BALANCE", "MODULATION_AMOUNT", "PULSE_WIDTH", "WAVE_SELECT" }; logerror("s%04X: CEM#%d:%s=%f\n", m_audiocpu->pcbase(), i, names[m_dac_register], voltage); } #endif } // if a timer for counter 0 is running, recompute if (m_counter_0_timer_active) update_counter_0_timer(); } WRITE8_MEMBER(sente6vb_device::dac_data_w) { // LSB or MSB? if (offset & 1) m_dac_value = (m_dac_value & 0xfc0) | ((data >> 2) & 0x03f); else m_dac_value = (m_dac_value & 0x03f) | ((data << 6) & 0xfc0); // if there are open channels, force the values in if ((m_chip_select & 0x3f) != 0x3f) { uint8_t temp = m_chip_select; chip_select_w(space, 0, 0x3f); chip_select_w(space, 0, temp); } } WRITE8_MEMBER(sente6vb_device::register_addr_w) { m_dac_register = data & 7; }