balsente.cpp: Use ACIA devices for sound communication

src/mame/drivers/balsente.cpp

@@ -231,6 +231,7 @@ DIP locations verified for:
 #include "cpu/z80/z80.h"
 #include "cpu/m6809/m6809.h"
 #include "cpu/m68000/m68000.h"
+#include "machine/clock.h"
 #include "machine/watchdog.h"
 #include "sound/cem3394.h"
 #include "speaker.h"
@@ -265,7 +266,7 @@ void balsente_state::cpu1_base_map(address_map &map)
 	map(0x9902, 0x9902).portr("IN0");
 	map(0x9903, 0x9903).portr("IN1").nopw();
 	map(0x9a00, 0x9a03).r(FUNC(balsente_state::random_num_r));
-	map(0x9a04, 0x9a05).rw(FUNC(balsente_state::m6850_r), FUNC(balsente_state::m6850_w));
+	map(0x9a04, 0x9a05).rw("acia", FUNC(acia6850_device::read), FUNC(acia6850_device::write));
 	map(0xa000, 0xbfff).bankr("bank1");
 	map(0xc000, 0xffff).bankr("bank2");
 }
@@ -295,8 +296,8 @@ void balsente_state::cpu2_map(address_map &map)
 {
 	map(0x0000, 0x1fff).rom();
 	map(0x2000, 0x5fff).ram();
-	map(0x6000, 0x7fff).w(FUNC(balsente_state::m6850_sound_w));
+	map(0x6000, 0x6001).mirror(0x1ffe).w("audiouart", FUNC(acia6850_device::write));
-	map(0xe000, 0xffff).r(FUNC(balsente_state::m6850_sound_r));
+	map(0xe000, 0xe001).mirror(0x1ffe).r("audiouart", FUNC(acia6850_device::read));
 }
 
 
@@ -1314,7 +1315,20 @@ MACHINE_CONFIG_START(balsente_state::balsente)
 	MCFG_DEVICE_PROGRAM_MAP(cpu2_map)
 	MCFG_DEVICE_IO_MAP(cpu2_io_map)
 
-	MCFG_QUANTUM_TIME(attotime::from_hz(600))
+	MCFG_DEVICE_ADD("acia", ACIA6850, 0)
+	MCFG_ACIA6850_TXD_HANDLER(WRITELINE("audiouart", acia6850_device, write_rxd))
+	MCFG_ACIA6850_IRQ_HANDLER(INPUTLINE("maincpu", M6809_FIRQ_LINE))
+
+	MCFG_DEVICE_ADD("audiouart", ACIA6850, 0)
+	MCFG_ACIA6850_TXD_HANDLER(WRITELINE("acia", acia6850_device, write_rxd))
+	MCFG_ACIA6850_IRQ_HANDLER(WRITELINE(*this, balsente_state, uint_w))
+
+	MCFG_DEVICE_ADD("uartclock", CLOCK, 8_MHz_XTAL / 16) // 500 kHz
+	MCFG_CLOCK_SIGNAL_HANDLER(WRITELINE(*this, balsente_state, uint_propagate_w))
+	MCFG_DEVCB_CHAIN_OUTPUT(WRITELINE("audiouart", acia6850_device, write_txc))
+	MCFG_DEVCB_CHAIN_OUTPUT(WRITELINE("audiouart", acia6850_device, write_rxc))
+	MCFG_DEVCB_CHAIN_OUTPUT(WRITELINE("acia", acia6850_device, write_txc)) MCFG_DEVCB_INVERT
+	MCFG_DEVCB_CHAIN_OUTPUT(WRITELINE("acia", acia6850_device, write_rxc)) MCFG_DEVCB_INVERT
 
 	MCFG_X2212_ADD_AUTOSAVE("nov0") // system NOVRAM
 	MCFG_X2212_ADD_AUTOSAVE("nov1") // cart NOVRAM

src/mame/includes/balsente.h

@@ -8,6 +8,7 @@
 
 ***************************************************************************/
 
+#include "machine/6850acia.h"
 #include "machine/pit8253.h"
 #include "machine/timer.h"
 #include "machine/x2212.h"
@@ -54,6 +55,8 @@ public:
 		, m_palette(*this, "palette")
 		, m_outlatch(*this, "outlatch")
 		, m_novram(*this, "nov%u", 0U)
+		, m_acia(*this, "acia")
+		, m_audiouart(*this, "audiouart")
 		, m_generic_paletteram_8(*this, "paletteram")
 	{ }
 
@@ -101,10 +104,8 @@ private:
 	DECLARE_WRITE_LINE_MEMBER(nvrecall_w);
 	DECLARE_READ8_MEMBER(novram_8bit_r);
 	DECLARE_WRITE8_MEMBER(novram_8bit_w);
-	DECLARE_READ8_MEMBER(m6850_r);
+	DECLARE_WRITE_LINE_MEMBER(uint_w);
-	DECLARE_WRITE8_MEMBER(m6850_w);
+	DECLARE_WRITE_LINE_MEMBER(uint_propagate_w);
-	DECLARE_READ8_MEMBER(m6850_sound_r);
-	DECLARE_WRITE8_MEMBER(m6850_sound_w);
 	DECLARE_READ8_MEMBER(adc_data_r);
 	DECLARE_WRITE8_MEMBER(adc_select_w);
 	DECLARE_READ8_MEMBER(counter_state_r);
@@ -135,14 +136,11 @@ private:
 	uint32_t screen_update_balsente(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
 	INTERRUPT_GEN_MEMBER(update_analog_inputs);
 	TIMER_CALLBACK_MEMBER(irq_off);
-	TIMER_CALLBACK_MEMBER(m6850_data_ready_callback);
-	TIMER_CALLBACK_MEMBER(m6850_w_callback);
 	TIMER_CALLBACK_MEMBER(adc_finished);
 	TIMER_DEVICE_CALLBACK_MEMBER(interrupt_timer);
 	TIMER_DEVICE_CALLBACK_MEMBER(clock_counter_0_ff);
 	void draw_one_sprite(bitmap_ind16 &bitmap, const rectangle &cliprect, uint8_t *sprite);
 	void poly17_init();
-	void m6850_update_io();
 	DECLARE_WRITE_LINE_MEMBER(set_counter_0_ff);
 	void update_grudge_steering();
 	void expand_roms(uint8_t cd_rom_mask);
@@ -191,18 +189,8 @@ private:
 	uint8_t m_dac_register;
 	uint8_t m_chip_select;
 
-	/* main CPU 6850 states */
-	uint8_t m_m6850_status;
-	uint8_t m_m6850_control;
-	uint8_t m_m6850_input;
-	uint8_t m_m6850_output;
-	uint8_t m_m6850_data_ready;
-
 	/* sound CPU 6850 states */
-	uint8_t m_m6850_sound_status;
+	bool m_uint;
-	uint8_t m_m6850_sound_control;
-	uint8_t m_m6850_sound_input;
-	uint8_t m_m6850_sound_output;
 
 	/* noise generator states */
 	uint32_t m_noise_position[6];
@@ -236,6 +224,8 @@ private:
 	required_device<palette_device> m_palette;
 	required_device<ls259_device> m_outlatch;
 	required_device_array<x2212_device, 2> m_novram;
+	required_device<acia6850_device> m_acia;
+	required_device<acia6850_device> m_audiouart;
 	required_shared_ptr<uint8_t> m_generic_paletteram_8;
 };
 

src/mame/machine/balsente.cpp

@@ -72,6 +72,11 @@ void balsente_state::machine_start()
 	/* create the polynomial tables */
 	poly17_init();
 
+	m_acia->write_cts(0);
+	m_acia->write_dcd(0);
+	m_audiouart->write_cts(0);
+	m_audiouart->write_dcd(0);
+
 	save_item(NAME(m_counter_control));
 	save_item(NAME(m_counter_0_ff));
 	save_item(NAME(m_counter_0_out));
@@ -84,16 +89,7 @@ void balsente_state::machine_start()
 	save_item(NAME(m_dac_register));
 	save_item(NAME(m_chip_select));
 
-	save_item(NAME(m_m6850_status));
+	save_item(NAME(m_uint));
-	save_item(NAME(m_m6850_control));
-	save_item(NAME(m_m6850_input));
-	save_item(NAME(m_m6850_output));
-	save_item(NAME(m_m6850_data_ready));
-
-	save_item(NAME(m_m6850_sound_status));
-	save_item(NAME(m_m6850_sound_control));
-	save_item(NAME(m_m6850_sound_input));
-	save_item(NAME(m_m6850_sound_output));
 
 	save_item(NAME(m_noise_position));
 
@@ -108,7 +104,6 @@ void balsente_state::machine_start()
 
 void balsente_state::machine_reset()
 {
-	address_space &space = m_maincpu->space(AS_PROGRAM);
 	int numbanks;
 
 	/* reset the manual counter 0 clock */
@@ -116,6 +111,7 @@ void balsente_state::machine_reset()
 	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 ADC states */
 	m_adc_value = 0;
@@ -128,10 +124,6 @@ void balsente_state::machine_reset()
 	/* reset game-specific states */
 	m_grudge_steering_result = 0;
 
-	/* reset the 6850 chips */
-	m6850_w(space, 0, 3);
-	m6850_sound_w(space, 0, 3);
-
 	/* reset the noise generator */
 	memset(m_noise_position, 0, sizeof(m_noise_position));
 
@@ -335,206 +327,15 @@ WRITE8_MEMBER(balsente_state::novram_8bit_w)
  *
  *************************************/
 
-void balsente_state::m6850_update_io()
+WRITE_LINE_MEMBER(balsente_state::uint_w)
 {
-	uint8_t new_state;
+	m_uint = bool(state);
-
-	/* sound -> main CPU communications */
-	if (!(m_m6850_sound_status & 0x02))
-	{
-		/* set the overrun bit if the data in the destination hasn't been read yet */
-		if (m_m6850_status & 0x01)
-			m_m6850_status |= 0x20;
-
-		/* copy the sound's output to our input */
-		m_m6850_input = m_m6850_sound_output;
-
-		/* set the receive register full bit */
-		m_m6850_status |= 0x01;
-
-		/* set the sound's trasmitter register empty bit */
-		m_m6850_sound_status |= 0x02;
-	}
-
-	/* main -> sound CPU communications */
-	if (m_m6850_data_ready)
-	{
-		/* set the overrun bit if the data in the destination hasn't been read yet */
-		if (m_m6850_sound_status & 0x01)
-			m_m6850_sound_status |= 0x20;
-
-		/* copy the main CPU's output to our input */
-		m_m6850_sound_input = m_m6850_output;
-
-		/* set the receive register full bit */
-		m_m6850_sound_status |= 0x01;
-
-		/* set the main CPU's trasmitter register empty bit */
-		m_m6850_status |= 0x02;
-		m_m6850_data_ready = 0;
-	}
-
-	/* check for reset states */
-	if ((m_m6850_control & 3) == 3)
-	{
-		m_m6850_status = 0x02;
-		m_m6850_data_ready = 0;
-	}
-	if ((m_m6850_sound_control & 3) == 3)
-		m_m6850_sound_status = 0x02;
-
-	/* check for transmit/receive IRQs on the main CPU */
-	new_state = 0;
-	if ((m_m6850_control & 0x80) && (m_m6850_status & 0x21)) new_state = 1;
-	if ((m_m6850_control & 0x60) == 0x20 && (m_m6850_status & 0x02)) new_state = 1;
-
-	/* apply the change */
-	if (new_state && !(m_m6850_status & 0x80))
-	{
-		m_maincpu->set_input_line(M6809_FIRQ_LINE, ASSERT_LINE);
-		m_m6850_status |= 0x80;
-	}
-	else if (!new_state && (m_m6850_status & 0x80))
-	{
-		m_maincpu->set_input_line(M6809_FIRQ_LINE, CLEAR_LINE);
-		m_m6850_status &= ~0x80;
-	}
-
-	/* check for transmit/receive IRQs on the sound CPU */
-	new_state = 0;
-	if ((m_m6850_sound_control & 0x80) && (m_m6850_sound_status & 0x21)) new_state = 1;
-	if ((m_m6850_sound_control & 0x60) == 0x20 && (m_m6850_sound_status & 0x02)) new_state = 1;
-	if (!(m_counter_control & 0x20)) new_state = 0;
-
-	/* apply the change */
-	if (new_state && !(m_m6850_sound_status & 0x80))
-	{
-		m_audiocpu->set_input_line(INPUT_LINE_NMI, ASSERT_LINE);
-		m_m6850_sound_status |= 0x80;
-	}
-	else if (!new_state && (m_m6850_sound_status & 0x80))
-	{
-		m_audiocpu->set_input_line(INPUT_LINE_NMI, CLEAR_LINE);
-		m_m6850_sound_status &= ~0x80;
-	}
 }
 
-
+WRITE_LINE_MEMBER(balsente_state::uint_propagate_w)
-
-/*************************************
- *
- *  6850 UART (main CPU)
- *
- *************************************/
-
-READ8_MEMBER(balsente_state::m6850_r)
 {
-	int result;
+	if (state && BIT(m_counter_control, 5))
-
+		m_audiocpu->set_input_line(INPUT_LINE_NMI, m_uint ? ASSERT_LINE : CLEAR_LINE);
-	/* status register is at offset 0 */
-	if (offset == 0)
-	{
-		result = m_m6850_status;
-	}
-
-	/* input register is at offset 1 */
-	else
-	{
-		result = m_m6850_input;
-
-		/* clear the overrun and receive buffer full bits */
-		m_m6850_status &= ~0x21;
-		m6850_update_io();
-	}
-
-	return result;
-}
-
-
-TIMER_CALLBACK_MEMBER(balsente_state::m6850_data_ready_callback)
-{
-	/* set the output data byte and indicate that we're ready to go */
-	m_m6850_output = param;
-	m_m6850_data_ready = 1;
-	m6850_update_io();
-}
-
-
-TIMER_CALLBACK_MEMBER(balsente_state::m6850_w_callback)
-{
-	/* indicate that the transmit buffer is no longer empty and update the I/O state */
-	m_m6850_status &= ~0x02;
-	m6850_update_io();
-
-	/* set a timer for 500usec later to actually transmit the data */
-	/* (this is very important for several games, esp Snacks'n Jaxson) */
-	machine().scheduler().timer_set(attotime::from_usec(500), timer_expired_delegate(FUNC(balsente_state::m6850_data_ready_callback),this), param);
-}
-
-
-WRITE8_MEMBER(balsente_state::m6850_w)
-{
-	/* control register is at offset 0 */
-	if (offset == 0)
-	{
-		m_m6850_control = data;
-
-		/* re-update since interrupt enables could have been modified */
-		m6850_update_io();
-	}
-
-	/* output register is at offset 1; set a timer to synchronize the CPUs */
-	else
-		machine().scheduler().synchronize(timer_expired_delegate(FUNC(balsente_state::m6850_w_callback),this), data);
-}
-
-
-
-/*************************************
- *
- *  6850 UART (sound CPU)
- *
- *************************************/
-
-READ8_MEMBER(balsente_state::m6850_sound_r)
-{
-	int result;
-
-	/* status register is at offset 0 */
-	if (offset == 0)
-	{
-		result = m_m6850_sound_status;
-	}
-
-	/* input register is at offset 1 */
-	else
-	{
-		result = m_m6850_sound_input;
-
-		/* clear the overrun and receive buffer full bits */
-		m_m6850_sound_status &= ~0x21;
-		m6850_update_io();
-	}
-
-	return result;
-}
-
-
-WRITE8_MEMBER(balsente_state::m6850_sound_w)
-{
-	/* control register is at offset 0 */
-	if (offset == 0)
-		m_m6850_sound_control = data;
-
-	/* output register is at offset 1 */
-	else
-	{
-		m_m6850_sound_output = data;
-		m_m6850_sound_status &= ~0x02;
-	}
-
-	/* re-update since interrupt enables could have been modified */
-	m6850_update_io();
 }
 
 
@@ -764,8 +565,9 @@ WRITE8_MEMBER(balsente_state::counter_control_w)
 	else if (!BIT(data, 2))
 		set_counter_0_ff(1);
 
-	/* bit 5 clears the NMI interrupt; recompute the I/O state now */
+	/* bit 5 clears the NMI interrupt */
-	m6850_update_io();
+	if (BIT(diff_counter_control, 5) && !BIT(data, 5))
+		m_audiocpu->set_input_line(INPUT_LINE_NMI, CLEAR_LINE);
 }