More accurate registration and acknowledgment of pending interrupts within TMP68301 interrupt controller

src/devices/machine/tmp68301.cpp

@@ -1,5 +1,5 @@
 // license:BSD-3-Clause
-// copyright-holders:Luca Elia
+// copyright-holders:Luca Elia, AJR
 /***************************************************************************
 
     TMP68301 basic emulation + Interrupt Handling
@@ -9,7 +9,7 @@
     all integrated in a single chip.
 
     TODO:
-    - Interrupt generation: handle pending / in-service mechanisms
+    - Interrupt generation: edge detection, input expansion (INT3-INT9)
     - Parallel port: handle timing latency
     - Serial port: not done at all
     - (and many other things)
@@ -27,6 +27,7 @@ void tmp68301_device::tmp68301_regs(address_map &map)
 	map(0x080, 0x093).rw(FUNC(tmp68301_device::icr_r), FUNC(tmp68301_device::icr_w)).umask16(0x00ff);
 
 	map(0x094, 0x095).rw(FUNC(tmp68301_device::imr_r), FUNC(tmp68301_device::imr_w));
+	map(0x096, 0x097).rw(FUNC(tmp68301_device::ipr_r), FUNC(tmp68301_device::ipr_w));
 	map(0x098, 0x099).rw(FUNC(tmp68301_device::iisr_r), FUNC(tmp68301_device::iisr_w));
 
 	/* Parallel Port */
@@ -37,7 +38,7 @@ void tmp68301_device::tmp68301_regs(address_map &map)
 	map(0x18e, 0x18f).rw(FUNC(tmp68301_device::scr_r), FUNC(tmp68301_device::scr_w));
 }
 
-// IRQ Mask register, 0x94
+// IRQ Mask register
 READ16_MEMBER(tmp68301_device::imr_r)
 {
 	return m_imr;
@@ -46,6 +47,20 @@ READ16_MEMBER(tmp68301_device::imr_r)
 WRITE16_MEMBER(tmp68301_device::imr_w)
 {
 	COMBINE_DATA(&m_imr);
+	update_ipl();
+}
+
+// IRQ Pending Register
+READ16_MEMBER(tmp68301_device::ipr_r)
+{
+	return m_ipr;
+}
+
+WRITE16_MEMBER(tmp68301_device::ipr_w)
+{
+	// software writes only clear bits
+	m_ipr &= data | ~mem_mask;
+	update_ipl();
 }
 
 // IRQ In-Service Register
@@ -56,7 +71,8 @@ READ16_MEMBER(tmp68301_device::iisr_r)
 
 WRITE16_MEMBER(tmp68301_device::iisr_w)
 {
-	COMBINE_DATA(&m_iisr);
+	// software writes only clear bits
+	m_iisr &= data | ~mem_mask;
 }
 
 // Serial Control Register (TODO: 8-bit wide)
@@ -123,7 +139,9 @@ tmp68301_device::tmp68301_device(const machine_config &mconfig, const char *tag,
 		m_cpu(*this, finder_base::DUMMY_TAG),
 		m_in_parallel_cb(*this),
 		m_out_parallel_cb(*this),
+		m_ipl(0),
 		m_imr(0),
+		m_ipr(0),
 		m_iisr(0),
 		m_scr(0),
 		m_pdir(0),
@@ -132,7 +150,6 @@ tmp68301_device::tmp68301_device(const machine_config &mconfig, const char *tag,
 {
 	memset(m_regs, 0, sizeof(m_regs));
 	memset(m_icr, 0, sizeof(m_icr));
-	memset(m_irq_vector, 0, sizeof(m_irq_vector));
 }
 
 
@@ -151,8 +168,9 @@ void tmp68301_device::device_start()
 
 	save_item(NAME(m_regs));
 	save_item(NAME(m_icr));
-	save_item(NAME(m_irq_vector));
+	save_item(NAME(m_ipl));
 	save_item(NAME(m_imr));
+	save_item(NAME(m_ipr));
 	save_item(NAME(m_iisr));
 	save_item(NAME(m_scr));
 	save_item(NAME(m_pdir));
@@ -165,8 +183,11 @@ void tmp68301_device::device_start()
 
 void tmp68301_device::device_reset()
 {
+	m_ipr = 0;
 	m_iisr = 0;
 	m_imr = 0x7f7; // mask all irqs
+	std::fill(std::begin(m_icr), std::end(m_icr), 0x07);
+	update_ipl();
 }
 
 //-------------------------------------------------
@@ -205,31 +226,50 @@ inline void tmp68301_device::write_word(offs_t address, uint16_t data)
 
 IRQ_CALLBACK_MEMBER(tmp68301_device::irq_callback)
 {
-	int vector = m_irq_vector[irqline];
+	uint8_t IVNR = m_regs[0x9a/2] & 0xe0;      // Interrupt Vector Number Register (IVNR)
-//  logerror("%s: irq callback returns %04X for level %x\n",machine().describe_context(),vector,int_level);
+
-	return vector;
+	for (int src : { 0, 7, 3, 1, 8, 4, 5, 9, 2 })
+	{
+		// check if the IPL matches
+		if (irqline == (m_icr[src] & 0x07))
+		{
+			// check if interrupt is pending and not masked out
+			u16 mask = (src > 2 ? 2 : 1) << src;
+			if ((m_ipr & mask) != 0 && (m_imr & mask) == 0)
+			{
+				// add cause to interrupt in-service register
+				m_iisr |= mask;
+
+				// no longer pending
+				m_ipr &= ~mask;
+				update_ipl();
+
+				// vary vector number by type
+				if (src > 6)
+					return IVNR | (src - 3);
+				else if (src > 2)
+					return IVNR | (src - 1) << 2 | serial_interrupt_cause(src - 3);
+				else /*if (BIT(m_icr[src], 5))*/ // TODO: use external vector otherwise
+					return IVNR | src;
+			}
+		}
+	}
+
+	// default vector
+	return IVNR | 0x1f;
 }
 
-TIMER_CALLBACK_MEMBER( tmp68301_device::timer_callback )
+TIMER_CALLBACK_MEMBER(tmp68301_device::timer_callback)
 {
 	int i = param;
 	uint16_t TCR  =   m_regs[(0x200 + i * 0x20)/2];
-	uint16_t ICR  =   m_regs[0x8e/2+i];    // Interrupt Controller Register (ICR7..9)
-	uint16_t IVNR =   m_regs[0x9a/2];      // Interrupt Vector Number Register (IVNR)
 
 //  logerror("s: callback timer %04X, j = %d\n",machine().describe_context(),i,tcount);
 
-	if  (   (TCR & 0x0004) &&   // INT
+	if (TCR & 0x0004)   // INT
-			!(m_imr & (0x100<<i))
-		)
 	{
-		int level = ICR & 0x0007;
+		m_ipr |= 0x100 << i;
-
+		update_ipl();
-		// Interrupt Vector Number Register (IVNR)
-		m_irq_vector[level]  =   IVNR & 0x00e0;
-		m_irq_vector[level]  +=  4+i;
-
-		m_cpu->set_input_line(level,HOLD_LINE);
 	}
 
 	if (TCR & 0x0080)   // N/1
@@ -243,7 +283,7 @@ TIMER_CALLBACK_MEMBER( tmp68301_device::timer_callback )
 	}
 }
 
-void tmp68301_device::update_timer( int i )
+void tmp68301_device::update_timer(int i)
 {
 	uint16_t TCR  =   m_regs[(0x200 + i * 0x20)/2];
 	uint16_t MAX1 =   m_regs[(0x204 + i * 0x20)/2];
@@ -289,71 +329,38 @@ void tmp68301_device::update_timer( int i )
 }
 
 /* Update the IRQ state based on all possible causes */
-void tmp68301_device::update_irq_state(uint16_t cause)
+void tmp68301_device::update_ipl()
 {
-	int i;
+	uint8_t new_ipl = 0;
 
-	/* Take care of external interrupts */
+	for (int src = 0; src < 10; src++)
-
-	uint16_t IVNR =   m_regs[0x9a/2];      // Interrupt Vector Number Register (IVNR)
-	// add cause to interrupt in-service register
-	m_iisr |= cause;
-
-	for (i = 0; i < 3; i++)
 	{
-		if ((m_iisr & 1 << i) && !(m_imr & (1<<i)))
+		u16 mask = (src > 2 ? 2 : 1) << src;
-		{
+		if ((m_ipr & mask) != 0 && (m_imr & mask) == 0 && new_ipl < (m_icr[src] & 0x07))
-			uint8_t current_ICR = m_icr[i];    // Interrupt Controller Register (ICR0..2)
+			new_ipl = m_icr[src] & 0x07;
-
-			// Interrupt Controller Register (ICR0..2)
-			int level = current_ICR & 0x0007;
-
-			// Interrupt Vector Number Register (IVNR)
-			m_irq_vector[level]  =   IVNR & 0x00e0;
-			m_irq_vector[level]  +=  i;
-
-			m_cpu->set_input_line(level,HOLD_LINE);
 	}
+
+	if (new_ipl != m_ipl)
+	{
+		if (m_ipl != 0)
+			m_cpu->set_input_line(m_ipl, CLEAR_LINE);
+		if (new_ipl != 0)
+			m_cpu->set_input_line(new_ipl, ASSERT_LINE);
+
+		m_ipl = new_ipl;
 	}
 }
 
-void tmp68301_device::update_irq_serial(uint16_t cause, uint8_t type)
+uint8_t tmp68301_device::serial_interrupt_cause(int channel)
 {
-	int i;
-	const uint8_t serial_irq_vector[3] = { 8, 0xc, 0x10 };
-
-	/* Take care of external interrupts */
-
-	uint16_t IVNR =   m_regs[0x9a/2];      // Interrupt Vector Number Register (IVNR)
-	// add cause to interrupt in-service register
-	m_iisr |= cause;
-
-	for (i = 4; i < 7; i++)
-	{
-		if ((m_iisr & 1 << i) && !(m_imr & (1<<i)))
-		{
-			uint8_t current_ICR = m_icr[i-1];    // Interrupt Controller Register (ICR0..2)
-
-			// Interrupt Controller Register (ICR0..2)
-			int level = current_ICR & 0x0007;
-
-			// Interrupt Vector Number Register (IVNR)
-			m_irq_vector[level]  =   IVNR & 0x00e0;
-			/*
-			 * channel number
-			 */
-			m_irq_vector[level]  +=  serial_irq_vector[i-4];
 	/*
 	 *  00 error occurred
 	 *  01 receive completed
 	 *  10 transmit ready
 	 *  11 interrupt cause cleared while interrupt pending
 	 */
-			m_irq_vector[level]  +=  type;
+	(void)channel;
-
+	return 3;
-			m_cpu->set_input_line(level,HOLD_LINE);
-		}
-	}
 }
 
 
@@ -387,6 +394,6 @@ WRITE16_MEMBER( tmp68301_device::regs_w )
 	}
 }
 
-void tmp68301_device::external_interrupt_0()    { update_irq_state(EXT_IRQ0); }
+void tmp68301_device::external_interrupt_0()    { m_ipr |= EXT_IRQ0; update_ipl(); }
-void tmp68301_device::external_interrupt_1()    { update_irq_state(EXT_IRQ1); }
+void tmp68301_device::external_interrupt_1()    { m_ipr |= EXT_IRQ1; update_ipl(); }
-void tmp68301_device::external_interrupt_2()    { update_irq_state(EXT_IRQ2); }
+void tmp68301_device::external_interrupt_2()    { m_ipr |= EXT_IRQ2; update_ipl(); }

src/devices/machine/tmp68301.h

@@ -40,6 +40,8 @@ public:
 private:
 	DECLARE_READ16_MEMBER(imr_r);
 	DECLARE_WRITE16_MEMBER(imr_w);
+	DECLARE_READ16_MEMBER(ipr_r);
+	DECLARE_WRITE16_MEMBER(ipr_w);
 	DECLARE_READ16_MEMBER(iisr_r);
 	DECLARE_WRITE16_MEMBER(iisr_w);
 	DECLARE_READ16_MEMBER(scr_r);
@@ -60,10 +62,10 @@ protected:
 	virtual space_config_vector memory_space_config() const override;
 
 private:
-	TIMER_CALLBACK_MEMBER( timer_callback );
+	TIMER_CALLBACK_MEMBER(timer_callback);
-	void update_timer( int i );
+	void update_timer(int i);
-	void update_irq_state(uint16_t cause);
+	void update_ipl();
-	void update_irq_serial(uint16_t cause, uint8_t type);
+	uint8_t serial_interrupt_cause(int channel);
 
 	static constexpr uint16_t EXT_IRQ0 = 1 << 0;
 	static constexpr uint16_t EXT_IRQ1 = 1 << 1;
@@ -89,9 +91,10 @@ private:
 
 	emu_timer *m_tmp68301_timer[3];        // 3 Timers
 
-	uint16_t m_irq_vector[8];
+	uint8_t m_ipl; // internal interrupt level
 
 	uint16_t m_imr;
+	uint16_t m_ipr;
 	uint16_t m_iisr;
 	uint16_t m_scr;
 	uint16_t m_pdir;

src/mame/drivers/seta.cpp

@@ -1378,7 +1378,6 @@ Note: on screen copyright is (c)1998 Coinmaster.
 #include "machine/msm6242.h"
 #include "machine/nvram.h"
 #include "machine/pit8253.h"
-#include "machine/tmp68301.h"
 #include "machine/watchdog.h"
 #include "sound/2203intf.h"
 #include "sound/2612intf.h"
@@ -9255,13 +9254,19 @@ MACHINE_CONFIG_END
                             Pro Mahjong Kiwame
 ***************************************************************************/
 
+WRITE_LINE_MEMBER(seta_state::kiwame_vblank)
+{
+	if (state)
+		m_tmp68301->external_interrupt_0();
+}
+
 MACHINE_CONFIG_START(seta_state::kiwame)
 
 	/* basic machine hardware */
 	MCFG_DEVICE_ADD(m_maincpu, M68000, 16000000)   /* 16 MHz */
 	MCFG_DEVICE_PROGRAM_MAP(kiwame_map)
-	/* lev 1-7 are the same. WARNING: the interrupt table is written to. */
+	MCFG_DEVICE_IRQ_ACKNOWLEDGE_DEVICE("tmp68301", tmp68301_device, irq_callback)
-	MCFG_DEVICE_VBLANK_INT_DRIVER("screen", seta_state,  irq1_line_hold)
+
 	tmp68301_device &tmp68301(TMP68301(config, "tmp68301", 0));
 	tmp68301.set_cputag(m_maincpu);
 	tmp68301.out_parallel_callback().set(FUNC(seta_state::kiwame_row_select_w));
@@ -9280,6 +9285,7 @@ MACHINE_CONFIG_START(seta_state::kiwame)
 	MCFG_SCREEN_VISIBLE_AREA(0*8, 56*8-1, 1*8, 31*8-1)
 	MCFG_SCREEN_UPDATE_DRIVER(seta_state, screen_update_seta_no_layers)
 	MCFG_SCREEN_PALETTE("palette")
+	MCFG_SCREEN_VBLANK_CALLBACK(WRITELINE(*this, seta_state, kiwame_vblank))
 
 	MCFG_DEVICE_ADD("gfxdecode", GFXDECODE, "palette", gfx_tndrcade)
 	MCFG_PALETTE_ADD("palette", 512)    /* sprites only */

src/mame/includes/seta.h

@@ -16,6 +16,7 @@
 #include "machine/gen_latch.h"
 #include "machine/ticket.h"
 #include "machine/timer.h"
+#include "machine/tmp68301.h"
 #include "machine/upd4701.h"
 #include "machine/upd4992.h"
 #include "sound/x1_010.h"
@@ -45,6 +46,7 @@ public:
 	seta_state(const machine_config &mconfig, device_type type, const char *tag) :
 		driver_device(mconfig, type, tag),
 		m_maincpu(*this,"maincpu"),
+		m_tmp68301(*this, "tmp68301"),
 		m_audiocpu(*this, "audiocpu"),
 		m_subcpu(*this,"sub"),
 		m_seta001(*this, "spritegen"),
@@ -147,6 +149,7 @@ public:
 
 protected:
 	required_device<cpu_device> m_maincpu;
+	optional_device<tmp68301_device> m_tmp68301;
 	optional_device<cpu_device> m_audiocpu;
 	optional_device<cpu_device> m_subcpu;
 	required_device<seta001_device> m_seta001;
@@ -300,6 +303,7 @@ protected:
 	TIMER_DEVICE_CALLBACK_MEMBER(tndrcade_sub_interrupt);
 	TIMER_DEVICE_CALLBACK_MEMBER(calibr50_interrupt);
 	TIMER_DEVICE_CALLBACK_MEMBER(crazyfgt_interrupt);
+	DECLARE_WRITE_LINE_MEMBER(kiwame_vblank);
 	void set_pens();
 	void usclssic_set_pens();
 	void draw_tilemap_palette_effect(bitmap_ind16 &bitmap, const rectangle &cliprect, tilemap_t *tilemap, int scrollx, int scrolly, int gfxnum, int flipscreen);