Incremental C++-ification of 6821pia.cpp

1.  Changed some 'int' ==> 'bool' where appropriate
2.  Changed the various control byte macros to static functions

src/devices/machine/6821pia.cpp

@@ -34,21 +34,6 @@
 #define PIA_IRQ1                (0x80)
 #define PIA_IRQ2                (0x40)
 
-#define IRQ1_ENABLED(c)         ( (((c) >> 0) & 0x01))
-#define C1_LOW_TO_HIGH(c)       ( (((c) >> 1) & 0x01))
-#define C1_HIGH_TO_LOW(c)       (!(((c) >> 1) & 0x01))
-#define OUTPUT_SELECTED(c)      ( (((c) >> 2) & 0x01))
-#define IRQ2_ENABLED(c)         ( (((c) >> 3) & 0x01))
-#define STROBE_E_RESET(c)       ( (((c) >> 3) & 0x01))
-#define STROBE_C1_RESET(c)      (!(((c) >> 3) & 0x01))
-#define C2_SET(c)               ( (((c) >> 3) & 0x01))
-#define C2_LOW_TO_HIGH(c)       ( (((c) >> 4) & 0x01))
-#define C2_HIGH_TO_LOW(c)       (!(((c) >> 4) & 0x01))
-#define C2_SET_MODE(c)          ( (((c) >> 4) & 0x01))
-#define C2_STROBE_MODE(c)       (!(((c) >> 4) & 0x01))
-#define C2_OUTPUT(c)            ( (((c) >> 5) & 0x01))
-#define C2_INPUT(c)             (!(((c) >> 5) & 0x01))
-
 
 //**************************************************************************
 //  LIVE DEVICE
@@ -211,7 +196,7 @@ void pia6821_device::device_reset()
 void pia6821_device::update_interrupts()
 {
 	// start with IRQ A
-	int new_state = (m_irq_a1 && IRQ1_ENABLED(m_ctl_a)) || (m_irq_a2 && IRQ2_ENABLED(m_ctl_a));
+	int new_state = (m_irq_a1 && irq1_enabled(m_ctl_a)) || (m_irq_a2 && irq2_enabled(m_ctl_a));
 
 	if (new_state != m_irq_a_state)
 	{
@@ -220,7 +205,7 @@ void pia6821_device::update_interrupts()
 	}
 
 	// then do IRQ B
-	new_state = (m_irq_b1 && IRQ1_ENABLED(m_ctl_b)) || (m_irq_b2 && IRQ2_ENABLED(m_ctl_b));
+	new_state = (m_irq_b1 && irq1_enabled(m_ctl_b)) || (m_irq_b2 && irq2_enabled(m_ctl_b));
 
 	if (new_state != m_irq_b_state)
 	{
@@ -430,13 +415,13 @@ uint8_t pia6821_device::port_a_r()
 	update_interrupts();
 
 	// CA2 is configured as output and in read strobe mode
-	if(C2_OUTPUT(m_ctl_a) && C2_STROBE_MODE(m_ctl_a))
+	if(c2_output(m_ctl_a) && c2_strobe_mode(m_ctl_a))
 	{
 		// this will cause a transition low
 		set_out_ca2(false);
 
 		// if the CA2 strobe is cleared by the E, reset it right away
-		if(STROBE_E_RESET(m_ctl_a))
+		if(strobe_e_reset(m_ctl_a))
 		{
 			set_out_ca2(true);
 		}
@@ -474,7 +459,7 @@ uint8_t pia6821_device::port_b_r()
 	// mode with CB1 restore, and a CB1 active transition set the flag,
 	// clearing it will cause CB2 to go high again.  Note that this is different
 	// from what happens with port A.
-	if(m_irq_b1 && C2_STROBE_MODE(m_ctl_b) && STROBE_C1_RESET(m_ctl_b))
+	if(m_irq_b1 && c2_strobe_mode(m_ctl_b) && strobe_c1_reset(m_ctl_b))
 	{
 		set_out_cb2(true);
 	}
@@ -527,7 +512,7 @@ uint8_t pia6821_device::control_a_r()
 	{
 		ca2_w(m_in_ca2_handler());
 	}
-	else if ( !m_logged_ca2_not_connected && C2_INPUT(m_ctl_a) && !m_in_ca2_pushed)
+	else if ( !m_logged_ca2_not_connected && c2_input(m_ctl_a) && !m_in_ca2_pushed)
 	{
 		logerror("PIA #%s: Warning! No CA2 read handler. Assuming pin not connected\n", tag());
 		m_logged_ca2_not_connected = true;
@@ -542,7 +527,7 @@ uint8_t pia6821_device::control_a_r()
 		ret |= PIA_IRQ1;
 	}
 
-	if(m_irq_a2 && C2_INPUT(m_ctl_a))
+	if(m_irq_a2 && c2_input(m_ctl_a))
 	{
 		ret |= PIA_IRQ2;
 	}
@@ -572,7 +557,7 @@ uint8_t pia6821_device::control_b_r()
 		m_logged_cb1_not_connected = true;
 	}
 
-	if(!m_logged_cb2_not_connected && C2_INPUT(m_ctl_b) && !m_in_cb2_pushed)
+	if(!m_logged_cb2_not_connected && c2_input(m_ctl_b) && !m_in_cb2_pushed)
 	{
 		logerror("PIA #%s: Error! Three-state pin is undefined\n", tag());
 		m_logged_cb2_not_connected = true;
@@ -587,7 +572,7 @@ uint8_t pia6821_device::control_b_r()
 		ret |= PIA_IRQ1;
 	}
 
-	if(m_irq_b2 && C2_INPUT(m_ctl_b))
+	if(m_irq_b2 && c2_input(m_ctl_b))
 	{
 		ret |= PIA_IRQ2;
 	}
@@ -610,7 +595,7 @@ uint8_t pia6821_device::reg_r(uint8_t offset)
 	{
 		default: // impossible
 		case 0x00:
-			if (OUTPUT_SELECTED(m_ctl_a))
+			if (output_selected(m_ctl_a))
 			{
 				ret = port_a_r();
 			}
@@ -625,7 +610,7 @@ uint8_t pia6821_device::reg_r(uint8_t offset)
 			break;
 
 		case 0x02:
-			if (OUTPUT_SELECTED(m_ctl_b))
+			if (output_selected(m_ctl_b))
 			{
 				ret = port_b_r();
 			}
@@ -753,13 +738,13 @@ void pia6821_device::port_b_w(uint8_t data)
 	send_to_out_b_func("port B write");
 
 	// CB2 in write strobe mode
-	if(C2_STROBE_MODE(m_ctl_b))
+	if(c2_strobe_mode(m_ctl_b))
 	{
 		// this will cause a transition low
 		set_out_cb2(false);
 
 		// if the CB2 strobe is cleared by the E, reset it right away
-		if(STROBE_E_RESET(m_ctl_b))
+		if(strobe_e_reset(m_ctl_b))
 		{
 			set_out_cb2(true);
 		}
@@ -811,14 +796,14 @@ void pia6821_device::control_a_w(uint8_t data)
 	m_ctl_a = data;
 
 	// CA2 is configured as output
-	if(C2_OUTPUT(m_ctl_a))
+	if(c2_output(m_ctl_a))
 	{
-		int temp;
+		bool temp;
 
-		if(C2_SET_MODE(m_ctl_a))
+		if(c2_set_mode(m_ctl_a))
 		{
 			// set/reset mode - bit value determines the new output
-			temp = C2_SET(m_ctl_a);
+			temp = c2_set(m_ctl_a);
 		}
 		else
 		{
@@ -840,7 +825,7 @@ void pia6821_device::control_a_w(uint8_t data)
 
 void pia6821_device::control_b_w(uint8_t data)
 {
-	int temp;
+	bool temp;
 
 	// bit 7 and 6 are read only
 	data &= 0x3f;
@@ -850,10 +835,10 @@ void pia6821_device::control_b_w(uint8_t data)
 	// update the control register
 	m_ctl_b = data;
 
-	if (C2_SET_MODE(m_ctl_b))
+	if (c2_set_mode(m_ctl_b))
 	{
 		// set/reset mode - bit value determines the new output
-		temp = C2_SET(m_ctl_b);
+		temp = c2_set(m_ctl_b);
 	}
 	else
 	{
@@ -878,7 +863,7 @@ void pia6821_device::reg_w(uint8_t offset, uint8_t data)
 	{
 		default: // impossible
 		case 0x00:
-			if (OUTPUT_SELECTED(m_ctl_a))
+			if (output_selected(m_ctl_a))
 			{
 				port_a_w(data);
 			}
@@ -893,7 +878,7 @@ void pia6821_device::reg_w(uint8_t offset, uint8_t data)
 			break;
 
 		case 0x02:
-			if(OUTPUT_SELECTED(m_ctl_b))
+			if(output_selected(m_ctl_b))
 			{
 				port_b_w(data);
 			}
@@ -957,7 +942,7 @@ WRITE_LINE_MEMBER( pia6821_device::ca1_w )
 	LOGCA1("PIA #%s: set input CA1 = %d\n", tag(), state);
 
 	// the new state has caused a transition
-	if((m_in_ca1 != state) && ((state && C1_LOW_TO_HIGH(m_ctl_a)) || (!state && C1_HIGH_TO_LOW(m_ctl_a))))
+	if((m_in_ca1 != state) && ((state && c1_low_to_high(m_ctl_a)) || (!state && c1_high_to_low(m_ctl_a))))
 	{
 		LOGCA1("PIA #%s: CA1 triggering\n", tag());
 
@@ -968,7 +953,7 @@ WRITE_LINE_MEMBER( pia6821_device::ca1_w )
 		update_interrupts();
 
 		// CA2 is configured as output and in read strobe mode and cleared by a CA1 transition
-		if(C2_OUTPUT(m_ctl_a) && C2_STROBE_MODE(m_ctl_a) && STROBE_C1_RESET(m_ctl_a))
+		if(c2_output(m_ctl_a) && c2_strobe_mode(m_ctl_a) && strobe_c1_reset(m_ctl_a))
 		{
 			set_out_ca2(true);
 		}
@@ -989,7 +974,7 @@ WRITE_LINE_MEMBER( pia6821_device::ca2_w )
 	LOG("PIA #%s: set input CA2 = %d\n", tag(), state);
 
 	// if input mode and the new state has caused a transition
-	if(C2_INPUT(m_ctl_a) && (m_in_ca2 != state) && ((state && C2_LOW_TO_HIGH(m_ctl_a)) || (!state && C2_HIGH_TO_LOW(m_ctl_a))))
+	if(c2_input(m_ctl_a) && (m_in_ca2 != state) && ((state && c2_low_to_high(m_ctl_a)) || (!state && c2_high_to_low(m_ctl_a))))
 	{
 		LOG("PIA #%s: CA2 triggering\n", tag());
 
@@ -1010,7 +995,7 @@ WRITE_LINE_MEMBER( pia6821_device::ca2_w )
 //  ca2_output
 //-------------------------------------------------
 
-int pia6821_device::ca2_output()
+bool pia6821_device::ca2_output()
 {
 	m_out_ca2_needs_pulled = false;
 
@@ -1023,13 +1008,13 @@ int pia6821_device::ca2_output()
 //  takes account of internal pullup resistor
 //-------------------------------------------------
 
-int pia6821_device::ca2_output_z()
+bool pia6821_device::ca2_output_z()
 {
 	m_out_ca2_needs_pulled = false;
 
 	// If it's an output, output the bit, if it's an input, it's
 	// pulled up
-	return m_out_ca2 | C2_INPUT(m_ctl_a);
+	return m_out_ca2 | c2_input(m_ctl_a);
 }
 
 
@@ -1069,7 +1054,7 @@ WRITE_LINE_MEMBER( pia6821_device::cb1_w )
 	LOG("PIA #%s: set input CB1 = %d\n", tag(), state);
 
 	// the new state has caused a transition
-	if((m_in_cb1 != state) && ((state && C1_LOW_TO_HIGH(m_ctl_b)) || (!state && C1_HIGH_TO_LOW(m_ctl_b))))
+	if((m_in_cb1 != state) && ((state && c1_low_to_high(m_ctl_b)) || (!state && c1_high_to_low(m_ctl_b))))
 	{
 		LOG("PIA #%s: CB1 triggering\n", tag());
 
@@ -1100,9 +1085,9 @@ WRITE_LINE_MEMBER( pia6821_device::cb2_w )
 	LOG("PIA #%s: set input CB2 = %d\n", tag(), state);
 
 	// if input mode and the new state has caused a transition
-	if (C2_INPUT(m_ctl_b) &&
+	if (c2_input(m_ctl_b) &&
 		(m_in_cb2 != state) &&
-		((state && C2_LOW_TO_HIGH(m_ctl_b)) || (!state && C2_HIGH_TO_LOW(m_ctl_b))))
+		((state && c2_low_to_high(m_ctl_b)) || (!state && c2_high_to_low(m_ctl_b))))
 	{
 		LOG("PIA #%s: CB2 triggering\n", tag());
 
@@ -1123,7 +1108,7 @@ WRITE_LINE_MEMBER( pia6821_device::cb2_w )
 //  output_cb2
 //-------------------------------------------------
 
-int pia6821_device::cb2_output()
+bool pia6821_device::cb2_output()
 {
 	m_out_cb2_needs_pulled = false;
 	
@@ -1135,7 +1120,27 @@ int pia6821_device::cb2_output()
 //  cb2_output_z
 //-------------------------------------------------
 
-int pia6821_device::cb2_output_z()
+bool pia6821_device::cb2_output_z()
 {
-	return !C2_OUTPUT(m_ctl_b);
+	return !c2_output(m_ctl_b);
 }
+
+
+//-------------------------------------------------
+//  control byte wrappers
+//-------------------------------------------------
+
+bool pia6821_device::irq1_enabled(uint8_t c)	{ return (c >> 0) & 0x01 ? true : false; }
+bool pia6821_device::c1_low_to_high(uint8_t c)	{ return (c >> 1) & 0x01 ? true : false; }
+bool pia6821_device::c1_high_to_low(uint8_t c)	{ return !(c >> 1) & 0x01 ? true : false; }
+bool pia6821_device::output_selected(uint8_t c)	{ return (c >> 2) & 0x01 ? true : false; }
+bool pia6821_device::irq2_enabled(uint8_t c)	{ return (c >> 3) & 0x01 ? true : false; }
+bool pia6821_device::strobe_e_reset(uint8_t c)	{ return (c >> 3) & 0x01 ? true : false; }
+bool pia6821_device::strobe_c1_reset(uint8_t c)	{ return !(c >> 3) & 0x01 ? true : false; }
+bool pia6821_device::c2_set(uint8_t c)			{ return (c >> 3) & 0x01 ? true : false; }
+bool pia6821_device::c2_low_to_high(uint8_t c)	{ return (c >> 4) & 0x01 ? true : false; }
+bool pia6821_device::c2_high_to_low(uint8_t c)	{ return !(c >> 4) & 0x01 ? true : false; }
+bool pia6821_device::c2_set_mode(uint8_t c)		{ return (c >> 4) & 0x01 ? true : false; }
+bool pia6821_device::c2_strobe_mode(uint8_t c)	{ return !(c >> 4) & 0x01 ? true : false; }
+bool pia6821_device::c2_output(uint8_t c)		{ return (c >> 5) & 0x01 ? true : false; }
+bool pia6821_device::c2_input(uint8_t c)		{ return !(c >> 5) & 0x01 ? true : false; }

src/devices/machine/6821pia.h

@@ -112,8 +112,8 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( ca1_w );
 
 	DECLARE_WRITE_LINE_MEMBER( ca2_w );
-	int ca2_output();
+	bool ca2_output();
-	int ca2_output_z();
+	bool ca2_output_z();
 
 	DECLARE_WRITE8_MEMBER( portb_w ) { portb_w(data); }
 	void portb_w(uint8_t data);
@@ -122,8 +122,8 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( cb1_w );
 
 	DECLARE_WRITE_LINE_MEMBER( cb2_w );
-	int cb2_output();
+	bool cb2_output();
-	int cb2_output_z();
+	bool cb2_output_z();
 
 	int irq_a_state() const { return m_irq_a_state; }
 	int irq_b_state() const { return m_irq_b_state; }
@@ -168,6 +168,21 @@ private:
 	void control_a_w(uint8_t data);
 	void control_b_w(uint8_t data);
 
+	static bool irq1_enabled(uint8_t c);
+	static bool c1_low_to_high(uint8_t c);
+	static bool c1_high_to_low(uint8_t c);
+	static bool output_selected(uint8_t c);
+	static bool irq2_enabled(uint8_t c);
+	static bool strobe_e_reset(uint8_t c);
+	static bool strobe_c1_reset(uint8_t c);
+	static bool c2_set(uint8_t c);
+	static bool c2_low_to_high(uint8_t c);
+	static bool c2_high_to_low(uint8_t c);
+	static bool c2_set_mode(uint8_t c);
+	static bool c2_strobe_mode(uint8_t c);
+	static bool c2_output(uint8_t c);
+	static bool c2_input(uint8_t c);
+
 	devcb_read8 m_in_a_handler;
 	devcb_read8 m_in_b_handler;
 	devcb_read_line m_in_ca1_handler;