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// license:BSD-3-Clause
// copyright-holders:Aaron Giles, Nathan Woods
/**********************************************************************
Motorola 6821 PIA interface and emulation
Notes:
* get_port_b_z_mask() gives the caller the bitmask that shows
which bits are high-impedance 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.
**********************************************************************/
#ifndef MAME_DEVICES_MACHINE_6821PIA_H
#define MAME_DEVICES_MACHINE_6821PIA_H
#pragma once
/***************************************************************************
TYPE DEFINITIONS
***************************************************************************/
// ======================> pia6821_device
class pia6821_device : public device_t
{
public:
// construction/destruction
pia6821_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock = 0);
// TODO: REMOVE THESE
auto readpa_handler() { return m_in_a_handler.bind(); }
auto readpb_handler() { return m_in_b_handler.bind(); }
auto readca1_handler() { return m_in_ca1_handler.bind(); }
auto readca2_handler() { return m_in_ca2_handler.bind(); }
auto readcb1_handler() { return m_in_cb1_handler.bind(); }
// TODO: CONVERT THESE TO WRITE LINE
auto writepa_handler() { return m_out_a_handler.bind(); }
auto writepb_handler() { return m_out_b_handler.bind(); }
auto ca2_handler() { return m_ca2_handler.bind(); }
auto cb2_handler() { return m_cb2_handler.bind(); }
auto irqa_handler() { return m_irqa_handler.bind(); }
auto irqb_handler() { return m_irqb_handler.bind(); }
uint8_t reg_r(uint8_t offset);
void reg_w(uint8_t offset, uint8_t data);
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_t port_b_z_mask() const { return ~m_ddr_b; } // see first note in .c
void set_port_a_z_mask(uint8_t data) { m_port_a_z_mask = data; }// see second note in .c
DECLARE_WRITE8_MEMBER( porta_w ) { write_porta(data); }
void write_porta(uint8_t data);
void set_a_input(uint8_t data, uint8_t z_mask);
uint8_t a_output();
DECLARE_WRITE_LINE_MEMBER( ca1_w );
DECLARE_WRITE_LINE_MEMBER( ca2_w );
bool ca2_output();
bool ca2_output_z();
DECLARE_WRITE8_MEMBER( portb_w ) { write_portb(data); }
void write_portb(uint8_t data);
uint8_t b_output();
DECLARE_WRITE_LINE_MEMBER( cb1_w );
DECLARE_WRITE_LINE_MEMBER( cb2_w );
bool cb2_output();
bool 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() override;
virtual void device_reset() override;
private:
void update_interrupts();
uint8_t get_in_a_value();
uint8_t get_in_b_value();
uint8_t get_out_a_value();
uint8_t get_out_b_value();
void set_out_ca2(int data);
void set_out_cb2(int data);
uint8_t port_a_r();
uint8_t ddr_a_r();
uint8_t control_a_r();
uint8_t port_b_r();
uint8_t ddr_b_r();
uint8_t 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_t data);
void ddr_a_w(uint8_t data);
void port_b_w(uint8_t data);
void ddr_b_w(uint8_t data);
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;
devcb_read_line m_in_cb1_handler;
devcb_read_line m_in_ca2_handler;
devcb_write8 m_out_a_handler;
devcb_write8 m_out_b_handler;
devcb_write_line m_ca2_handler;
devcb_write_line m_cb2_handler;
devcb_write_line m_irqa_handler;
devcb_write_line m_irqb_handler;
uint8_t m_in_a;
uint8_t m_in_ca1;
uint8_t m_in_ca2;
uint8_t m_out_a;
uint8_t m_out_ca2;
uint8_t m_port_a_z_mask;
uint8_t m_ddr_a;
uint8_t m_ctl_a;
uint8_t m_irq_a1;
uint8_t m_irq_a2;
uint8_t m_irq_a_state;
uint8_t m_in_b;
uint8_t m_in_cb1;
uint8_t m_in_cb2;
uint8_t m_out_b;
uint8_t m_out_cb2;
uint8_t m_last_out_cb2_z;
uint8_t m_ddr_b;
uint8_t m_ctl_b;
uint8_t m_irq_b1;
uint8_t m_irq_b2;
uint8_t 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
DECLARE_DEVICE_TYPE(PIA6821, pia6821_device)
#endif // MAME_DEVICES_MACHINE_6821PIA_H
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