6522VIA: Implemented CA2 pulse output mode, and output interrupt state only when it changes. [Curt Coder]

6532RIOT: Output interrupt state only when it changes. [Curt Coder]

src/emu/machine/6522via.c

@@ -109,6 +109,15 @@
     INLINE FUNCTIONS
 ***************************************************************************/
 
+inline void via6522_device::set_irq_line(int state)
+{
+	if (m_irq != state)
+	{
+		m_irq_func(state);
+		m_irq = state;
+	}
+}
+
 attotime via6522_device::cycles_to_time(int c)
 {
 	return attotime::from_hz(clock()) * c;
@@ -150,7 +159,8 @@ const device_type VIA6522 = &device_creator<via6522_device>;
 //-------------------------------------------------
 
 via6522_device::via6522_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
-    : device_t(mconfig, VIA6522, "6522 VIA", tag, owner, clock)
+    : device_t(mconfig, VIA6522, "6522 VIA", tag, owner, clock),
+	  m_irq(CLEAR_LINE)
 {
 
 }
@@ -214,6 +224,7 @@ void via6522_device::device_start()
     m_time2 = m_time1 = machine().time();
     m_t1 = timer_alloc(TIMER_T1);
     m_t2 = timer_alloc(TIMER_T2);
+    m_ca2_timer = timer_alloc(TIMER_CA2);
     m_shift_timer = timer_alloc(TIMER_SHIFT);
 
 	/* Default clock is from CPU1 */
@@ -248,6 +259,7 @@ void via6522_device::device_start()
     save_item(NAME(m_acr));
     save_item(NAME(m_ier));
     save_item(NAME(m_ifr));
+	save_item(NAME(m_irq));
     save_item(NAME(m_t1_active));
     save_item(NAME(m_t2_active));
     save_item(NAME(m_shift_counter));
@@ -304,7 +316,7 @@ void via6522_device::set_int(int data)
 	if (m_ier & m_ifr)
     {
 		m_ifr |= INT_ANY;
-		m_irq_func(ASSERT_LINE);
+		set_irq_line(ASSERT_LINE);
     }
 }
 
@@ -328,7 +340,7 @@ void via6522_device::clear_int(int data)
     }
 	else
 	{
-		m_irq_func(CLEAR_LINE);
+		set_irq_line(CLEAR_LINE);
 	}
 }
 
@@ -459,6 +471,11 @@ void via6522_device::device_timer(emu_timer &timer, device_timer_id id, int para
 				set_int(INT_T2);
 		    }
 		    break;
+			
+		case TIMER_CA2:
+			m_out_ca2_func(1);
+			m_out_ca2 = 1;
+			break;
 	}
 }
 
@@ -528,7 +545,17 @@ READ8_MEMBER( via6522_device::read )
 
 		/* If CA2 is configured as output and in pulse or handshake mode,
            CA2 is set now */
-		if (CA2_AUTO_HS(m_pcr))
+		if (CA2_PULSE_OUTPUT(m_pcr))
+		{
+			/* call the CA2 output function */
+			m_out_ca2_func(0);
+			m_out_ca2 = 0;
+			
+			m_ca2_timer->adjust(cycles_to_time(1));
+		}
+		/* If CA2 is configured as output and in pulse or handshake mode,
+           CA2 is set now */
+		else if (CA2_AUTO_HS(m_pcr))
 		{
 			if (m_out_ca2)
 			{
@@ -712,10 +739,9 @@ WRITE8_MEMBER( via6522_device::write )
 		{
 			/* call the CA2 output function */
 			m_out_ca2_func(0);
-			m_out_ca2_func(1);
+			m_out_ca2 = 0;
-
+			
-			/* set CA2 (shouldn't be needed) */
+			m_ca2_timer->adjust(cycles_to_time(1));
-			m_out_ca2 = 1;
 		}
 		else if (CA2_AUTO_HS(m_pcr))
 		{
@@ -902,7 +928,7 @@ WRITE8_MEMBER( via6522_device::write )
 			if (((m_ifr & m_ier) & 0x7f) == 0)
 			{
 				m_ifr &= ~INT_ANY;
-				m_irq_func(CLEAR_LINE);
+				set_irq_line(CLEAR_LINE);
 			}
 		}
 		else
@@ -910,7 +936,7 @@ WRITE8_MEMBER( via6522_device::write )
 			if ((m_ier & m_ifr) & 0x7f)
 			{
 				m_ifr |= INT_ANY;
-				m_irq_func(ASSERT_LINE);
+				set_irq_line(ASSERT_LINE);
 			}
 		}
 		break;

src/emu/machine/6522via.h

@@ -119,11 +119,13 @@ private:
 	static const device_timer_id TIMER_SHIFT = 0;
 	static const device_timer_id TIMER_T1 = 1;
 	static const device_timer_id TIMER_T2 = 2;
+	static const device_timer_id TIMER_CA2 = 3;
 
     attotime cycles_to_time(int c);
     UINT32 time_to_cycles(attotime t);
     UINT16 get_counter1_value();
 
+	inline void set_irq_line(int state);
     void set_int(int data);
     void clear_int(int data);
     void shift();
@@ -170,6 +172,7 @@ private:
     UINT8 m_acr;
     UINT8 m_ier;
     UINT8 m_ifr;
+	int m_irq;
 
     emu_timer *m_t1;
     attotime m_time1;
@@ -177,6 +180,7 @@ private:
     emu_timer *m_t2;
     attotime m_time2;
     UINT8 m_t2_active;
+	emu_timer *m_ca2_timer;
 
     emu_timer *m_shift_timer;
     UINT8 m_shift_counter;

src/emu/machine/6532riot.c

@@ -46,15 +46,12 @@ enum
 
 void riot6532_device::update_irqstate()
 {
-	int state = (m_irqstate & m_irqenable);
+	int irq = (m_irqstate & m_irqenable) ? ASSERT_LINE : CLEAR_LINE;
 
-	if (!m_irq_func.isnull())
+	if (m_irq != irq)
 	{
-		m_irq_func((state != 0) ? ASSERT_LINE : CLEAR_LINE);
+		m_irq_func(irq);
-	}
+		m_irq = irq;
-	else
-	{
-		logerror("%s:6532RIOT chip #%d: no irq callback function\n", machine().describe_context(), m_index);
 	}
 }
 
@@ -229,14 +226,7 @@ void riot6532_device::reg_w(UINT8 offset, UINT8 data)
 		else
 		{
 			port->m_out = data;
-			if (!port->m_out_func.isnull())
+			port->m_out_func(0, data);
-			{
-				port->m_out_func(0, data);
-			}
-			else
-			{
-				logerror("%s:6532RIOT chip %s: Port %c is being written to but has no handler. %02X\n", machine().describe_context(), tag(), 'A' + (offset & 1), data);
-			}
 		}
 
 		/* writes to port A need to update the PA7 state */
@@ -311,19 +301,12 @@ UINT8 riot6532_device::reg_r(UINT8 offset)
 		else
 		{
 			/* call the input callback if it exists */
-			if (!port->m_in_func.isnull())
+			port->m_in = port->m_in_func(0);
-			{
-				port->m_in = port->m_in_func(0);
 
-				/* changes to port A need to update the PA7 state */
+			/* changes to port A need to update the PA7 state */
-				if (port == &m_port[0])
+			if (port == &m_port[0])
-				{
-					update_pa7_state();
-				}
-			}
-			else
 			{
-				logerror("%s:6532RIOT chip %s: Port %c is being read but has no handler\n", machine().describe_context(), tag(), 'A' + (offset & 1));
+				update_pa7_state();
 			}
 
 			/* apply the DDR to the result */
@@ -440,7 +423,8 @@ UINT8 riot6532_device::portb_out_get()
 //-------------------------------------------------
 
 riot6532_device::riot6532_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
-	: device_t(mconfig, RIOT6532, "6532 (RIOT)", tag, owner, clock)
+	: device_t(mconfig, RIOT6532, "6532 (RIOT)", tag, owner, clock),
+	  m_irq(CLEAR_LINE)
 {
 }
 
@@ -506,6 +490,7 @@ void riot6532_device::device_start()
 
 	save_item(NAME(m_irqstate));
 	save_item(NAME(m_irqenable));
+	save_item(NAME(m_irq));
 
 	save_item(NAME(m_pa7dir));
 	save_item(NAME(m_pa7prev));

src/emu/machine/6532riot.h

@@ -98,6 +98,7 @@ private:
 
     UINT8           m_irqstate;
     UINT8           m_irqenable;
+	int				m_irq;
 
     UINT8           m_pa7dir;     /* 0x80 = high-to-low, 0x00 = low-to-high */
     UINT8           m_pa7prev;