I8251.hh

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// This class implements the Intel 8251 chip (UART)

#ifndef I8251_HH
#define I8251_HH

#include "ClockPin.hh"
#include "SerialDataInterface.hh"
#include "Schedulable.hh"
#include "openmsx.hh"

namespace openmsx {

class I8251Interface : public SerialDataInterface
{
public:
        virtual ~I8251Interface() {}
        virtual void setRxRDY(bool status, EmuTime::param time) = 0;
        virtual void setDTR(bool status, EmuTime::param time) = 0;
        virtual void setRTS(bool status, EmuTime::param time) = 0;
        virtual bool getDSR(EmuTime::param time) = 0;
        virtual bool getCTS(EmuTime::param time) = 0; // TODO use this
        virtual void signal(EmuTime::param time) = 0;
};

class I8251 : public SerialDataInterface, public Schedulable
{
public:
        I8251(Scheduler& scheduler, I8251Interface& interf, EmuTime::param time);

        void reset(EmuTime::param time);
        byte readIO(word port, EmuTime::param time);
        byte peekIO(word port, EmuTime::param time) const;
        void writeIO(word port, byte value, EmuTime::param time);
        ClockPin& getClockPin();
        bool isRecvReady();
        bool isRecvEnabled();

        // SerialDataInterface
        virtual void setDataBits(DataBits bits);
        virtual void setStopBits(StopBits bits);
        virtual void setParityBit(bool enable, ParityBit parity);
        virtual void recvByte(byte value, EmuTime::param time);

        // Schedulable
        virtual void executeUntil(EmuTime::param time, int userData);

        template<typename Archive>
        void serialize(Archive& ar, unsigned version);

        // public for serialize
        enum CmdFaze {
                FAZE_MODE, FAZE_SYNC1, FAZE_SYNC2, FAZE_CMD
        };

private:
        void setMode(byte mode);
        void writeCommand(byte value, EmuTime::param time);
        byte readStatus(EmuTime::param time);
        byte readTrans(EmuTime::param time);
        void writeTrans(byte value, EmuTime::param time);
        void send(byte value, EmuTime::param time);

        I8251Interface& interf;
        ClockPin clock;
        unsigned charLength;

        CmdFaze cmdFaze;
        SerialDataInterface::DataBits  recvDataBits;
        SerialDataInterface::StopBits  recvStopBits;
        SerialDataInterface::ParityBit recvParityBit;
        bool                           recvParityEnabled;
        byte                           recvBuf;
        bool recvReady;

        byte sendByte;
        byte sendBuffer;

        byte status;
        byte command;
        byte mode;
        byte sync1, sync2;
};

} // namespace openmsx

#endif