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CLK/Components/6522/6522.hpp
Thomas Harte 24b3faa427 Deconstitutes the 6522 into component parts, templated and non-templated.
Adjusts the Oric, Vic-20 and C-1540 accordingly, albeit with the quickest possible solutions.
2017-09-04 14:26:04 -04:00

112 lines
2.6 KiB
C++

//
// 6522.hpp
// Clock Signal
//
// Created by Thomas Harte on 06/06/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#ifndef _522_hpp
#define _522_hpp
#include <cstdint>
#include <typeinfo>
#include <cstdio>
#include "Implementation/6522Storage.hpp"
#include "../../ClockReceiver/ClockReceiver.hpp"
namespace MOS {
namespace MOS6522 {
enum Port {
A = 0,
B = 1
};
enum Line {
One = 0,
Two = 1
};
class PortHandler {
public:
uint8_t get_port_input(Port port) { return 0xff; }
void set_port_output(Port port, uint8_t value, uint8_t direction_mask) {}
void set_control_line_output(Port port, Line line, bool value) {}
void set_interrupt_status(bool status) {}
};
/*!
Provided for optional composition with @c MOS6522, @c MOS6522IRQDelegate provides for a delegate
that will receive IRQ line change notifications.
*/
class IRQDelegatePortHandler: public PortHandler {
public:
class Delegate {
public:
virtual void mos6522_did_change_interrupt_status(void *mos6522) = 0;
};
void set_interrupt_delegate(Delegate *delegate);
void set_interrupt_status(bool new_status);
private:
Delegate *delegate_ = nullptr;
};
class MOS6522Base: public MOS6522Storage {
public:
void set_control_line_input(Port port, Line line, bool value);
/*! Runs for a specified number of half cycles. */
void run_for(const HalfCycles half_cycles);
/*! Runs for a specified number of cycles. */
void run_for(const Cycles cycles);
/*! @returns @c true if the IRQ line is currently active; @c false otherwise. */
bool get_interrupt_line();
private:
inline void do_phase1();
inline void do_phase2();
virtual void reevaluate_interrupts() = 0;
};
/*!
Implements a template for emulation of the MOS 6522 Versatile Interface Adaptor ('VIA').
The VIA provides:
* two timers, each of which may trigger interrupts and one of which may repeat;
* two digial input/output ports; and
* a serial-to-parallel shifter.
Consumers should derive their own curiously-recurring-template-pattern subclass,
implementing bus communications as required.
*/
template <class T> class MOS6522: public MOS6522Base {
public:
MOS6522(T &bus_handler) : bus_handler_(bus_handler) {}
/*! Sets a register value. */
void set_register(int address, uint8_t value);
/*! Gets a register value. */
uint8_t get_register(int address);
private:
T &bus_handler_;
uint8_t get_port_input(Port port, uint8_t output_mask, uint8_t output);
inline void reevaluate_interrupts();
};
#include "Implementation/6522Implementation.hpp"
}
}
#endif /* _522_hpp */