// $Id: I8255.hh 5929 2006-12-15 18:21:09Z manuelbi $

// This class implements the Intel 8255 chip
//
// * Only the 8255 is emulated, no surrounding hardware.
//   Use the class I8255Interface to do that.
// * Only mode 0 (basic input/output) is implemented

#ifndef I8255_HH
#define I8255_HH

#include "openmsx.hh"
#include "noncopyable.hh"

namespace openmsx {

class EmuTime;
class MSXCliComm;

class I8255Interface
{
public:
	virtual ~I8255Interface() {}
	virtual byte readA(const EmuTime& time) = 0;
	virtual byte readB(const EmuTime& time) = 0;
	virtual nibble readC0(const EmuTime& time) = 0;
	virtual nibble readC1(const EmuTime& time) = 0;
	virtual byte peekA(const EmuTime& time) const = 0;
	virtual byte peekB(const EmuTime& time) const = 0;
	virtual nibble peekC0(const EmuTime& time) const = 0;
	virtual nibble peekC1(const EmuTime& time) const = 0;
	virtual void writeA(byte value, const EmuTime& time) = 0;
	virtual void writeB(byte value, const EmuTime& time) = 0;
	virtual void writeC0(nibble value, const EmuTime& time) = 0;
	virtual void writeC1(nibble value, const EmuTime& time) = 0;
};

class I8255 : private noncopyable
{
public:
	I8255(I8255Interface& interf, const EmuTime& time,
		MSXCliComm& cliComm);
	~I8255();

	void reset(const EmuTime& time);

	byte readPortA(const EmuTime& time);
	byte readPortB(const EmuTime& time);
	byte readPortC(const EmuTime& time);
	byte readControlPort(const EmuTime& time) const;
	byte peekPortA(const EmuTime& time) const;
	byte peekPortB(const EmuTime& time) const;
	byte peekPortC(const EmuTime& time) const;
	void writePortA(byte value, const EmuTime& time);
	void writePortB(byte value, const EmuTime& time);
	void writePortC(byte value, const EmuTime& time);
	void writeControlPort(byte value, const EmuTime& time);

private:
	byte readC0(const EmuTime& time);
	byte readC1(const EmuTime& time);
	byte peekC0(const EmuTime& time) const;
	byte peekC1(const EmuTime& time) const;
	void outputPortA(byte value, const EmuTime& time);
	void outputPortB(byte value, const EmuTime& time);
	void outputPortC(byte value, const EmuTime& time);

	int control;
	int latchPortA;
	int latchPortB;
	int latchPortC;

	I8255Interface& interface;

	MSXCliComm& cliComm;

	bool warningPrinted;
};

} // namespace openmsx

#endif