Supermodel/Src/Model3/IRQ.h
Matthew Daniels 9ffce8b92a Getting rid of most of the includes from Supermodel.h; each file now explicitly includes the header files it needs.
Making changes to a header file should no longer force the entire project to recompile.
2021-11-22 17:15:06 +00:00

151 lines
3.5 KiB
C++

/**
** Supermodel
** A Sega Model 3 Arcade Emulator.
** Copyright 2011 Bart Trzynadlowski, Nik Henson
**
** This file is part of Supermodel.
**
** Supermodel is free software: you can redistribute it and/or modify it under
** the terms of the GNU General Public License as published by the Free
** Software Foundation, either version 3 of the License, or (at your option)
** any later version.
**
** Supermodel is distributed in the hope that it will be useful, but WITHOUT
** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
** more details.
**
** You should have received a copy of the GNU General Public License along
** with Supermodel. If not, see <http://www.gnu.org/licenses/>.
**/
/*
* IRQ.h
*
* Header file defining the CIRQ class: Model 3 IRQ controller.
*/
#ifndef INCLUDED_IRQ_H
#define INCLUDED_IRQ_H
#include "BlockFile.h"
#include "Types.h"
/*
* CIRQ:
*
* Model 3 IRQ controller.
*/
class CIRQ
{
public:
/*
* SaveState(SaveState):
*
* Saves an image of the current device state.
*
* Parameters:
* SaveState Block file to save state information to.
*/
void SaveState(CBlockFile *SaveState);
/*
* LoadState(SaveState):
*
* Loads and a state image.
*
* Parameters:
* SaveState Block file to load state information from.
*/
void LoadState(CBlockFile *SaveState);
/*
* Assert(irqBits):
*
* Assert IRQ(s). Also asserts the CPU IRQ line (unless no IRQs are
* actually asserted). The IRQ controller only tracks 8 state bits but for
* non-maskable interrupts, higher bits (bits 9 and above) can be used.
* They will be tracked internally but not visible when external hardware
* tries reading the IRQ state.
*
* Parameters:
* irqBits IRQ bits corresponding to the IRQ state register (1
* indicates assertion, 0 does nothing).
*/
void Assert(unsigned irqBits);
/*
* Deassert(irqBits):
*
* Deasserts the specified IRQs and, if there are no pending IRQs left,
* deasserts the CPU IRQ line.
*
* Parameters:
* irqBits IRQ bits corresponding to the IRQ state register (1
* indicates deassertion, 0 does nothing).
*/
void Deassert(unsigned irqBits);
/*
* ReadIRQEnable(void):
*
* Returns:
* The 8-bit IRQ enable register.
*/
UINT8 ReadIRQEnable(void);
/*
* WriteIRQEnable(data):
*
* Write to the IRQ enable register. A 1 indicates the IRQ is enabled. Only
* the first 8 IRQs can be masked.
*
* Parameters:
* data IRQ enable bits (8 bits).
*/
void WriteIRQEnable(UINT8 data);
/*
* ReadIRQState(void):
*
* Accesses the IRQ state register. Set bits indicate pending IRQs. Only
* the low 8 bits are returned. Any IRQs occupying bits above this are
* effectively invisible and non-maskable.
*
* Returns:
* The 8-bit IRQ state register.
*/
UINT8 ReadIRQState(void);
/*
* Reset(void):
*
* Resets the IRQ controller. All IRQs are disabled.
*/
void Reset(void);
/*
* Init(void):
*
* One-time initialization of the context. Must be called prior to all
* other members.
*/
void Init(void);
/*
* CIRQ(void):
* ~CIRQ(void):
*
* Constructor and destructor.
*/
CIRQ(void);
~CIRQ(void);
private:
unsigned irqEnable; // 8 bits, 1=enabled, 0=disabled
unsigned irqState; // bits correspond to irqEnable, 1=pending, 0=not pending
};
#endif // INCLUDED_IRQ_H