New callback for generic_latch_8/16_device (nw)

- Add MCFG_GENERIC_LATCH_DATA_PENDING_CB to raise and lower a line automatically as the latch is written and read. This should make sound IRQs easier to deliver and reduce the incidence of HOLD_LINE in drivers.
- Update a few drivers to use this new callback.

src/devices/machine/gen_latch.cpp

@@ -5,6 +5,7 @@
     Generic 8bit and 16 bit latch devices
 
 ***************************************************************************/
+
 #include "emu.h"
 #include "gen_latch.h"
 
@@ -13,26 +14,70 @@
 //**************************************************************************
 
 const device_type GENERIC_LATCH_8 = &device_creator<generic_latch_8_device>;
-
+const device_type GENERIC_LATCH_16 = &device_creator<generic_latch_16_device>;
 
 //**************************************************************************
 //  LIVE DEVICE
 //**************************************************************************
 
+//-------------------------------------------------
+//  generic_latch_base_device - constructor
+//-------------------------------------------------
+
+generic_latch_base_device::generic_latch_base_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, u32 clock, const char *shortname, const char *source) :
+	device_t(mconfig, type, name, tag, owner, clock, shortname, source),
+	m_latch_read(false),
+	m_data_pending_cb(*this)
+{
+}
+
+//-------------------------------------------------
+//  device_start - device-specific startup
+//-------------------------------------------------
+
+void generic_latch_base_device::device_start()
+{
+	m_data_pending_cb.resolve_safe();
+	save_item(NAME(m_latch_read));
+}
+
+//-------------------------------------------------
+//  pending_r - tell whether the latch is waiting
+//  to be read
+//-------------------------------------------------
+
+READ_LINE_MEMBER(generic_latch_base_device::pending_r)
+{
+	return !m_latch_read;
+}
+
+//-------------------------------------------------
+//  set_latch_read - helper to signal that latch
+//  has been read or is waiting to be read
+//-------------------------------------------------
+
+void generic_latch_base_device::set_latch_read(bool latch_read)
+{
+	if (m_latch_read != latch_read)
+	{
+		m_latch_read = latch_read;
+		m_data_pending_cb(!latch_read);
+	}
+}
+
 //-------------------------------------------------
 //  generic_latch_8_device - constructor
 //-------------------------------------------------
 
-generic_latch_8_device::generic_latch_8_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+generic_latch_8_device::generic_latch_8_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
-	device_t(mconfig, GENERIC_LATCH_8, "Generic 8-bit latch", tag, owner, clock, "generic_latch_8", __FILE__),
+	generic_latch_base_device(mconfig, GENERIC_LATCH_8, "Generic 8-bit latch", tag, owner, clock, "generic_latch_8", __FILE__),
-	m_latched_value(0),
+	m_latched_value(0)
-	m_latch_read(0)
 {
 }
 
 READ8_MEMBER( generic_latch_8_device::read )
 {
-	m_latch_read = 1;
+	set_latch_read(true);
 	return m_latched_value;
 }
 
@@ -66,17 +111,17 @@ WRITE_LINE_MEMBER( generic_latch_8_device::clear_w )
 //  callback to set a latch value
 //-------------------------------------------------
 
-void generic_latch_8_device::sync_callback(void *ptr, int32_t param)
+void generic_latch_8_device::sync_callback(void *ptr, s32 param)
 {
-	uint8_t value = param;
+	u8 value = param;
 
 	// if the latch hasn't been read and the value is changed, log a warning
-	if (!m_latch_read && m_latched_value != value)
+	if (!is_latch_read() && m_latched_value != value)
-		logerror("Warning: latch %s written before being read. Previous: %02x, new: %02x\n", tag(), m_latched_value, value);
+		logerror("Warning: latch written before being read. Previous: %02x, new: %02x\n", m_latched_value, value);
 
 	// store the new value and mark it not read
 	m_latched_value = value;
-	m_latch_read = 0;
+	set_latch_read(false);
 }
 
 //-------------------------------------------------
@@ -86,35 +131,23 @@ void generic_latch_8_device::sync_callback(void *ptr, int32_t param)
 void generic_latch_8_device::device_start()
 {
 	// register for state saving
+	generic_latch_base_device::device_start();
 	save_item(NAME(m_latched_value));
-	save_item(NAME(m_latch_read));
 }
 
-//**************************************************************************
-//  DEVICE DEFINITIONS
-//**************************************************************************
-
-const device_type GENERIC_LATCH_16 = &device_creator<generic_latch_16_device>;
-
-
-//**************************************************************************
-//  LIVE DEVICE
-//**************************************************************************
-
 //-------------------------------------------------
 //  generic_latch_16_device - constructor
 //-------------------------------------------------
 
-generic_latch_16_device::generic_latch_16_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+generic_latch_16_device::generic_latch_16_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
-	device_t(mconfig, GENERIC_LATCH_16, "Generic 16-bit latch", tag, owner, clock, "generic_latch_16", __FILE__),
+	generic_latch_base_device(mconfig, GENERIC_LATCH_16, "Generic 16-bit latch", tag, owner, clock, "generic_latch_16", __FILE__),
-	m_latched_value(0),
+	m_latched_value(0)
-	m_latch_read(0)
 {
 }
 
 READ16_MEMBER( generic_latch_16_device::read )
 {
-	m_latch_read = 1;
+	set_latch_read(true);
 	return m_latched_value;
 }
 
@@ -148,17 +181,17 @@ WRITE_LINE_MEMBER( generic_latch_16_device::clear_w )
 //  callback to set a latch value
 //-------------------------------------------------
 
-void generic_latch_16_device::sync_callback(void *ptr, int32_t param)
+void generic_latch_16_device::sync_callback(void *ptr, s32 param)
 {
-	uint16_t value = param;
+	u16 value = param;
 
 	// if the latch hasn't been read and the value is changed, log a warning
-	if (!m_latch_read && m_latched_value != value)
+	if (!is_latch_read() && m_latched_value != value)
-		logerror("Warning: latch %s written before being read. Previous: %02x, new: %02x\n", tag(), m_latched_value, value);
+		logerror("Warning: latch written before being read. Previous: %02x, new: %02x\n", m_latched_value, value);
 
 	// store the new value and mark it not read
 	m_latched_value = value;
-	m_latch_read = 0;
+	set_latch_read(false);
 }
 
 //-------------------------------------------------
@@ -168,6 +201,6 @@ void generic_latch_16_device::sync_callback(void *ptr, int32_t param)
 void generic_latch_16_device::device_start()
 {
 	// register for state saving
+	generic_latch_base_device::device_start();
 	save_item(NAME(m_latched_value));
-	save_item(NAME(m_latch_read));
 }

src/devices/machine/gen_latch.h

@@ -11,6 +11,8 @@
 #ifndef __GEN_LATCH_H__
 #define __GEN_LATCH_H__
 
+#include "emu.h"
+
 //**************************************************************************
 //  INTERFACE CONFIGURATION MACROS
 //**************************************************************************
@@ -21,17 +23,46 @@
 #define MCFG_GENERIC_LATCH_16_ADD(_tag) \
 	MCFG_DEVICE_ADD(_tag, GENERIC_LATCH_16, 0)
 
+#define MCFG_GENERIC_LATCH_DATA_PENDING_CB(_devcb) \
+	devcb = &generic_latch_base_device::set_data_pending_callback(*device, DEVCB_##_devcb);
+
 //**************************************************************************
 //  TYPE DEFINITIONS
 //**************************************************************************
 
+// ======================> generic_latch_base_device
+
+class generic_latch_base_device : public device_t
+{
+protected:
+	// construction/destruction
+	generic_latch_base_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, u32 clock, const char *shortname, const char *source);
+
+public:
+	// static configuration
+	template<class _Object> static devcb_base &set_data_pending_callback(device_t &device, _Object object) { return downcast<generic_latch_base_device &>(device).m_data_pending_cb.set_callback(object); }
+
+	DECLARE_READ_LINE_MEMBER(pending_r);
+
+protected:
+	virtual void device_start() override;
+
+	bool is_latch_read() const { return m_latch_read; }
+	void set_latch_read(bool latch_read);
+
+private:
+	bool                    m_latch_read;
+	devcb_write_line        m_data_pending_cb;				
+};
+
+
 // ======================> generic_latch_8_device
 
-class generic_latch_8_device : public device_t
+class generic_latch_8_device : public generic_latch_base_device
 {
 public:
 	// construction/destruction
-	generic_latch_8_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+	generic_latch_8_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
 
 	DECLARE_READ8_MEMBER( read );
 	DECLARE_WRITE8_MEMBER( write );
@@ -41,15 +72,15 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( preset_w );
 	DECLARE_WRITE_LINE_MEMBER( clear_w );
 
-	void preset_w(uint16_t value) { m_latched_value = value; }
+	void preset_w(u8 value) { m_latched_value = value; }
 
 protected:
 	virtual void device_start() override;
 
-	void sync_callback(void *ptr, int32_t param);
+	void sync_callback(void *ptr, s32 param);
+
 private:
-	uint16_t                  m_latched_value;
+	u8                      m_latched_value;
-	uint8_t                   m_latch_read;
 };
 
 // device type definition
@@ -58,11 +89,11 @@ extern const device_type GENERIC_LATCH_8;
 
 // ======================> generic_latch_16_device
 
-class generic_latch_16_device : public device_t
+class generic_latch_16_device : public generic_latch_base_device
 {
 public:
 	// construction/destruction
-	generic_latch_16_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+	generic_latch_16_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
 
 	DECLARE_READ16_MEMBER( read );
 	DECLARE_WRITE16_MEMBER( write );
@@ -72,13 +103,15 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( preset_w );
 	DECLARE_WRITE_LINE_MEMBER( clear_w );
 
+	void preset_w(u16 value) { m_latched_value = value; }
+
 protected:
 	virtual void device_start() override;
 
-	void sync_callback(void *ptr, int32_t param);
+	void sync_callback(void *ptr, s32 param);
+
 private:
-	uint16_t                  m_latched_value;
+	u16                     m_latched_value;
-	uint8_t                   m_latch_read;
 };
 
 // device type definition

src/mame/drivers/dec0.cpp

@@ -229,10 +229,7 @@ WRITE16_MEMBER(dec0_automat_state::automat_control_w)
 	{
 		case 0xe: /* z80 sound cpu */
 			if (ACCESSING_BITS_0_7)
-			{
 				m_soundlatch->write(space, 0, data & 0xff);
-				m_audiocpu->set_input_line(0, HOLD_LINE);
-			}
 			break;
 
 		case 12: /* DMA flag */
@@ -282,15 +279,6 @@ WRITE16_MEMBER(dec0_state::midres_sound_w)
 	}
 }
 
-WRITE16_MEMBER(dec0_automat_state::secretab_sound_w)
-{
-	if (ACCESSING_BITS_0_7)
-	{
-		m_soundlatch->write(space, 0, data & 0xff);
-		m_audiocpu->set_input_line(0, HOLD_LINE);
-	}
-}
-
 /******************************************************************************/
 
 static ADDRESS_MAP_START( dec0_map, AS_PROGRAM, 16, dec0_state )
@@ -621,7 +609,7 @@ static ADDRESS_MAP_START( secretab_map, AS_PROGRAM, 16, dec0_automat_state )
 //  AM_RANGE(0x340400, 0x3407ff) AM_DEVREADWRITE("tilegen1", deco_bac06_device, pf_rowscroll_r, pf_rowscroll_w)
 
 	AM_RANGE(0x314008, 0x31400f) AM_READ(slyspy_controls_r)
-	AM_RANGE(0x314000, 0x314001) AM_WRITE(secretab_sound_w)
+	AM_RANGE(0x314000, 0x314001) AM_DEVWRITE8("soundlatch", generic_latch_8_device, write, 0x00ff)
 
 	AM_RANGE(0x300000, 0x300007) AM_RAM
 	AM_RANGE(0x300010, 0x300017) AM_RAM
@@ -640,7 +628,7 @@ static ADDRESS_MAP_START( automat_s_map, AS_PROGRAM, 8, dec0_automat_state )
 	AM_RANGE(0xc000, 0xc7ff) AM_RAM
 	AM_RANGE(0xc800, 0xc801) AM_DEVREADWRITE("2203a", ym2203_device, read, write)
 	AM_RANGE(0xd000, 0xd001) AM_DEVREADWRITE("2203b", ym2203_device, read, write)
-	AM_RANGE(0xd800, 0xd800) AM_READ(sound_command_r)
+	AM_RANGE(0xd800, 0xd800) AM_DEVREAD("soundlatch", generic_latch_8_device, read)
 	AM_RANGE(0xe000, 0xe000) AM_DEVWRITE("adpcm_select2", ls157_device, ba_w)
 	AM_RANGE(0xe800, 0xe800) AM_WRITE(sound_bankswitch_w)
 	AM_RANGE(0xf000, 0xf000) AM_DEVWRITE("adpcm_select1", ls157_device, ba_w)
@@ -652,7 +640,7 @@ static ADDRESS_MAP_START( secretab_s_map, AS_PROGRAM, 8, dec0_automat_state )
 	AM_RANGE(0xc000, 0xc7ff) AM_RAM
 	AM_RANGE(0xc800, 0xc801) AM_DEVREADWRITE("2203a", ym2203_device, read, write)
 	AM_RANGE(0xd000, 0xd001) AM_DEVREADWRITE("ym3812", ym3812_device, read, write)
-	AM_RANGE(0xd800, 0xd800) AM_READ(sound_command_r)
+	AM_RANGE(0xd800, 0xd800) AM_DEVREAD("soundlatch", generic_latch_8_device, read)
 	AM_RANGE(0xe000, 0xe000) AM_DEVWRITE("adpcm_select2", ls157_device, ba_w)
 	AM_RANGE(0xe800, 0xe800) AM_WRITE(sound_bankswitch_w)
 	AM_RANGE(0xf000, 0xf000) AM_DEVWRITE("adpcm_select1", ls157_device, ba_w)
@@ -1385,12 +1373,6 @@ static MACHINE_CONFIG_DERIVED( dec1, dec0_base )
 MACHINE_CONFIG_END
 
 
-READ8_MEMBER(dec0_automat_state::sound_command_r)
-{
-	m_audiocpu->set_input_line(0, CLEAR_LINE);
-	return m_soundlatch->read(space, 0);
-}
-
 WRITE8_MEMBER(dec0_automat_state::sound_bankswitch_w)
 {
 	m_msm1->reset_w(BIT(data, 3));
@@ -1462,6 +1444,7 @@ static MACHINE_CONFIG_START( automat, dec0_automat_state )
 	MCFG_SPEAKER_STANDARD_MONO("mono")
 
 	MCFG_GENERIC_LATCH_8_ADD("soundlatch")
+	MCFG_GENERIC_LATCH_DATA_PENDING_CB(INPUTLINE("audiocpu", 0))
 
 	MCFG_SOUND_ADD("2203a", YM2203, 1250000)
 	MCFG_SOUND_ROUTE(0, "mono", 0.90)
@@ -1536,6 +1519,7 @@ static MACHINE_CONFIG_START( secretab, dec0_automat_state )
 	MCFG_SPEAKER_STANDARD_MONO("mono")
 
 	MCFG_GENERIC_LATCH_8_ADD("soundlatch")
+	MCFG_GENERIC_LATCH_DATA_PENDING_CB(INPUTLINE("audiocpu", 0))
 
 	MCFG_SOUND_ADD("2203a", YM2203, 1250000)
 	MCFG_SOUND_ROUTE(0, "mono", 0.90)

src/mame/drivers/discoboy.cpp

@@ -88,7 +88,6 @@ public:
 	DECLARE_WRITE8_MEMBER(rambank_select_w);
 	DECLARE_WRITE8_MEMBER(discoboy_port_00_w);
 	DECLARE_WRITE8_MEMBER(discoboy_port_01_w);
-	DECLARE_WRITE8_MEMBER(discoboy_port_03_w);
 	DECLARE_WRITE8_MEMBER(discoboy_port_06_w);
 	DECLARE_WRITE8_MEMBER(rambank_w);
 	DECLARE_READ8_MEMBER(rambank_r);
@@ -249,14 +248,6 @@ WRITE8_MEMBER(discoboy_state::discoboy_port_01_w)
 	membank("bank1")->set_entry(data & 0x07);
 }
 
-WRITE8_MEMBER(discoboy_state::discoboy_port_03_w)// sfx? (to sound cpu)
-{
-	//  printf("unk discoboy_port_03_w %02x\n", data);
-	//  m_audiocpu->set_input_line(INPUT_LINE_NMI, HOLD_LINE);
-	m_soundlatch->write(space, 0, data);
-	m_audiocpu->set_input_line(0, HOLD_LINE);
-}
-
 WRITE8_MEMBER(discoboy_state::discoboy_port_06_w)
 {
 	//printf("unk discoboy_port_06_w %02x\n",data);
@@ -333,7 +324,7 @@ static ADDRESS_MAP_START( io_map, AS_IO, 8, discoboy_state )
 	AM_RANGE(0x00, 0x00) AM_READ_PORT("DSWA") AM_WRITE(discoboy_port_00_w)
 	AM_RANGE(0x01, 0x01) AM_READ_PORT("SYSTEM") AM_WRITE(discoboy_port_01_w)
 	AM_RANGE(0x02, 0x02) AM_READ_PORT("P1")
-	AM_RANGE(0x03, 0x03) AM_READ_PORT("P2") AM_WRITE(discoboy_port_03_w)
+	AM_RANGE(0x03, 0x03) AM_READ_PORT("P2") AM_DEVWRITE("soundlatch", generic_latch_8_device, write)
 	AM_RANGE(0x04, 0x04) AM_READ_PORT("DSWB")
 	AM_RANGE(0x06, 0x06) AM_READWRITE(discoboy_port_06_r, discoboy_port_06_w) // ???
 	AM_RANGE(0x07, 0x07) AM_WRITE(rambank_select_w) // 0x20 is palette bank bit.. others?
@@ -512,6 +503,7 @@ static MACHINE_CONFIG_START( discoboy, discoboy_state )
 	MCFG_SPEAKER_STANDARD_STEREO("lspeaker", "rspeaker")
 
 	MCFG_GENERIC_LATCH_8_ADD("soundlatch")
+	MCFG_GENERIC_LATCH_DATA_PENDING_CB(INPUTLINE("audiocpu", 0))
 
 	MCFG_SOUND_ADD("ymsnd", YM3812, XTAL_10MHz/4)   /* 2.5 MHz? */
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "lspeaker", 0.6)

src/mame/includes/dec0.h

@@ -134,14 +134,12 @@ public:
 	uint16_t m_automat_scroll_regs[4];
 
 	DECLARE_WRITE16_MEMBER(automat_control_w);
-	DECLARE_WRITE16_MEMBER(secretab_sound_w);
 	DECLARE_READ16_MEMBER( automat_palette_r );
 	DECLARE_WRITE16_MEMBER( automat_palette_w );
 	DECLARE_WRITE16_MEMBER( automat_scroll_w )
 	{
 		COMBINE_DATA(&m_automat_scroll_regs[offset]);
 	}
-	DECLARE_READ8_MEMBER(sound_command_r);
 	DECLARE_WRITE8_MEMBER(sound_bankswitch_w);
 	DECLARE_WRITE_LINE_MEMBER(msm1_vclk_cb);
 	DECLARE_WRITE_LINE_MEMBER(msm2_vclk_cb);