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+/**********************************************************************
+
+ Motorola 6821 PIA interface and emulation
+
+ Notes:
+ * get_port_b_z_mask() gives the caller the bitmask that shows
+ which bits are high-impendance when reading port B, and thus
+ neither 0 or 1. get_output_cb2_z() returns the same info
+ for the CB2 pin.
+ * set_port_a_z_mask allows the input callback to indicate
+ which port A bits are disconnected. For these bits, the
+ read operation will return the output buffer's contents.
+ * The 'alt' interface functions are used when the A0 and A1
+ address bits are swapped.
+ * All 'int' data or return values are bool, and should be
+ converted to bool at some point.
+
+**********************************************************************/
+
+#pragma once
+
+#ifndef __6821PIA_H__
+#define __6821PIA_H__
+
+#include "emu.h"
+
+
+
+/***************************************************************************
+ DEVICE CONFIGURATION MACROS
+***************************************************************************/
+
+#define MCFG_PIA6821_ADD(_tag, _intrf) \
+ MCFG_DEVICE_ADD(_tag, PIA6821, 0) \
+ pia6821_device::static_set_interface(*device, _intrf);
+
+#define MCFG_PIA6821_MODIFY(_tag, _intrf) \
+ MCFG_DEVICE_MODIFY(_tag) \
+ pia6821_device::static_set_interface(*device, _intrf);
+
+#define MCFG_PIA6822_ADD(_tag, _intrf) \
+ MCFG_DEVICE_ADD(_tag, PIA6822, 0) \
+ pia6821_device::static_set_interface(*device, _intrf);
+
+#define MCFG_PIA6822_MODIFY(_tag, _intrf) \
+ MCFG_DEVICE_MODIFY(_tag) \
+ pia6821_device::static_set_interface(*device, _intrf);
+
+
+
+/***************************************************************************
+ TYPE DEFINITIONS
+***************************************************************************/
+
+
+// ======================> pia6821_interface
+
+struct pia6821_interface
+{
+ devcb_read8 m_in_a_cb;
+ devcb_read8 m_in_b_cb;
+ devcb_read_line m_in_ca1_cb;
+ devcb_read_line m_in_cb1_cb;
+ devcb_read_line m_in_ca2_cb;
+ devcb_read_line m_in_cb2_cb;
+ devcb_write8 m_out_a_cb;
+ devcb_write8 m_out_b_cb;
+ devcb_write_line m_out_ca2_cb;
+ devcb_write_line m_out_cb2_cb;
+ devcb_write_line m_irq_a_cb;
+ devcb_write_line m_irq_b_cb;
+};
+
+
+
+// ======================> pia6821_device
+
+class pia6821_device : public device_t,
+ public pia6821_interface
+{
+public:
+ // construction/destruction
+ pia6821_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+ // static configuration helpers
+ static void static_set_interface(device_t &device, const pia6821_interface &interface);
+
+ DECLARE_READ8_MEMBER( read ) { return reg_r(offset); }
+ DECLARE_WRITE8_MEMBER( write ) { reg_w(offset, data); }
+ DECLARE_READ8_MEMBER( read_alt ) { return reg_r(((offset << 1) & 0x02) | ((offset >> 1) & 0x01)); }
+ DECLARE_WRITE8_MEMBER( write_alt ) { reg_w(((offset << 1) & 0x02) | ((offset >> 1) & 0x01), data); }
+
+ UINT8 port_b_z_mask() const { return ~m_ddr_b; } // see first note in .c
+ void set_port_a_z_mask(UINT8 data) { m_port_a_z_mask = data; }// see second note in .c
+
+ DECLARE_READ8_MEMBER( porta_r );
+ UINT8 porta_r() { return porta_r(*machine().memory().first_space(), 0); }
+ DECLARE_WRITE8_MEMBER( porta_w );
+ void porta_w(UINT8 data) { porta_w(*machine().memory().first_space(), 0, data); }
+ void set_a_input(UINT8 data, UINT8 z_mask);
+ UINT8 a_output();
+
+ DECLARE_READ_LINE_MEMBER( ca1_r );
+ DECLARE_WRITE_LINE_MEMBER( ca1_w );
+
+ DECLARE_READ_LINE_MEMBER( ca2_r );
+ DECLARE_WRITE_LINE_MEMBER( ca2_w );
+ int ca2_output();
+ int ca2_output_z();
+
+ DECLARE_READ8_MEMBER( portb_r );
+ UINT8 portb_r() { return portb_r(*machine().memory().first_space(), 0); }
+ DECLARE_WRITE8_MEMBER( portb_w );
+ void portb_w(UINT8 data) { portb_w(*machine().memory().first_space(), 0, data); }
+ UINT8 b_output();
+
+ DECLARE_READ_LINE_MEMBER( cb1_r );
+ DECLARE_WRITE_LINE_MEMBER( cb1_w );
+
+ DECLARE_READ_LINE_MEMBER( cb2_r );
+ DECLARE_WRITE_LINE_MEMBER( cb2_w );
+ int cb2_output();
+ int cb2_output_z();
+
+ int irq_a_state() const { return m_irq_a_state; }
+ int irq_b_state() const { return m_irq_b_state; }
+
+protected:
+ // device-level overrides
+ virtual void device_start();
+ virtual void device_reset();
+
+private:
+ UINT8 reg_r(UINT8 offset);
+ void reg_w(UINT8 offset, UINT8 data);
+
+ void update_interrupts();
+
+ UINT8 get_in_a_value();
+ UINT8 get_in_b_value();
+
+ UINT8 get_out_a_value();
+ UINT8 get_out_b_value();
+
+ void set_out_ca2(int data);
+ void set_out_cb2(int data);
+
+ UINT8 port_a_r();
+ UINT8 ddr_a_r();
+ UINT8 control_a_r();
+
+ UINT8 port_b_r();
+ UINT8 ddr_b_r();
+ UINT8 control_b_r();
+
+ void send_to_out_a_func(const char* message);
+ void send_to_out_b_func(const char* message);
+
+ void port_a_w(UINT8 data);
+ void ddr_a_w(UINT8 data);
+
+ void port_b_w(UINT8 data);
+ void ddr_b_w(UINT8 data);
+
+ void control_a_w(UINT8 data);
+ void control_b_w(UINT8 data);
+
+ devcb_resolved_read8 m_in_a_func;
+ devcb_resolved_read8 m_in_b_func;
+ devcb_resolved_read_line m_in_ca1_func;
+ devcb_resolved_read_line m_in_cb1_func;
+ devcb_resolved_read_line m_in_ca2_func;
+ devcb_resolved_read_line m_in_cb2_func;
+ devcb_resolved_write8 m_out_a_func;
+ devcb_resolved_write8 m_out_b_func;
+ devcb_resolved_write_line m_out_ca2_func;
+ devcb_resolved_write_line m_out_cb2_func;
+ devcb_resolved_write_line m_irq_a_func;
+ devcb_resolved_write_line m_irq_b_func;
+
+ UINT8 m_in_a;
+ UINT8 m_in_ca1;
+ UINT8 m_in_ca2;
+ UINT8 m_out_a;
+ UINT8 m_out_ca2;
+ UINT8 m_port_a_z_mask;
+ UINT8 m_ddr_a;
+ UINT8 m_ctl_a;
+ UINT8 m_irq_a1;
+ UINT8 m_irq_a2;
+ UINT8 m_irq_a_state;
+
+ UINT8 m_in_b;
+ UINT8 m_in_cb1;
+ UINT8 m_in_cb2;
+ UINT8 m_out_b;
+ UINT8 m_out_cb2;
+ UINT8 m_last_out_cb2_z;
+ UINT8 m_ddr_b;
+ UINT8 m_ctl_b;
+ UINT8 m_irq_b1;
+ UINT8 m_irq_b2;
+ UINT8 m_irq_b_state;
+
+ // variables that indicate if access a line externally -
+ // used to for logging purposes ONLY
+ bool m_in_a_pushed;
+ bool m_out_a_needs_pulled;
+ bool m_in_ca1_pushed;
+ bool m_in_ca2_pushed;
+ bool m_out_ca2_needs_pulled;
+ bool m_in_b_pushed;
+ bool m_out_b_needs_pulled;
+ bool m_in_cb1_pushed;
+ bool m_in_cb2_pushed;
+ bool m_out_cb2_needs_pulled;
+ bool m_logged_port_a_not_connected;
+ bool m_logged_port_b_not_connected;
+ bool m_logged_ca1_not_connected;
+ bool m_logged_ca2_not_connected;
+ bool m_logged_cb1_not_connected;
+ bool m_logged_cb2_not_connected;
+};
+
+
+// device type definition
+extern const device_type PIA6821;
+
+
+#endif /* __6821PIA_H__ */