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◆ main openmsx / src / serial / MC6850.hh
2.4 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
e8555c89 Andy McCall 1 
#ifndef MC6850_HH
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#define MC6850_HH
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#include "MidiInConnector.hh"
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#include "MidiOutConnector.hh"
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#include "DynamicClock.hh"
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#include "IRQHelper.hh"
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#include "Schedulable.hh"
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#include "outer.hh"
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#include <cstdint>
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namespace openmsx {
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class Scheduler;
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class MC6850 final : public MidiInConnector
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{
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public:
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	MC6850(const std::string& name, MSXMotherBoard& motherBoard, unsigned clockFreq);
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	void reset(EmuTime time);
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	[[nodiscard]] uint8_t readStatusReg() const;
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	[[nodiscard]] uint8_t peekStatusReg() const;
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	[[nodiscard]] uint8_t readDataReg();
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	[[nodiscard]] uint8_t peekDataReg() const;
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	void writeControlReg(uint8_t value, EmuTime time);
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	void writeDataReg   (uint8_t value, EmuTime time);
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        template<typename Archive>
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	void serialize(Archive& ar, unsigned version);
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private:
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	void setDataFormat();
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	// MidiInConnector
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	[[nodiscard]] bool ready() override;
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	[[nodiscard]] bool acceptsData() override;
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	void setDataBits(DataBits bits) override;
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	void setStopBits(StopBits bits) override;
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	void setParityBit(bool enable, Parity parity) override;
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	void recvByte(uint8_t value, EmuTime time) override;
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	// Schedulable
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	struct SyncRecv final : Schedulable {
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		friend class MC6850;
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		explicit SyncRecv(Scheduler& s) : Schedulable(s) {}
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		void executeUntil(EmuTime time) override {
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			auto& mc6850 = OUTER(MC6850, syncRecv);
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			mc6850.execRecv(time);
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		}
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	} syncRecv;
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	struct SyncTrans final : Schedulable {
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		friend class MC6850;
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		explicit SyncTrans(Scheduler& s) : Schedulable(s) {}
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		void executeUntil(EmuTime time) override {
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			auto& mc6850 = OUTER(MC6850, syncTrans);
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			mc6850.execTrans(time);
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		}
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	} syncTrans;
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	void execRecv (EmuTime time);
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	void execTrans(EmuTime time);
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	// External clock, divided by 1, 16 or 64.
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	// Transmitted bits are synced to this clock
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	DynamicClock txClock{EmuTime::zero()};
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	const unsigned clockFreq;
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	IRQHelper rxIRQ;
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	IRQHelper txIRQ;
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	bool rxReady;
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	bool txShiftRegValid; //<! True iff txShiftReg contains a valid value
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	bool pendingOVRN;     //<! Overrun detected but not yet reported.
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	uint8_t rxDataReg;       //<! Byte received from MIDI in connector.
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	uint8_t txDataReg = 0;   //<! Next to-be-sent byte.
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	uint8_t txShiftReg = 0;  //<! Byte currently being sent.
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	uint8_t controlReg;
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	uint8_t statusReg;
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	uint8_t charLen;         //<! #start- + #data- + #parity- + #stop-bits
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	MidiOutConnector outConnector;
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};
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SERIALIZE_CLASS_VERSION(MC6850, 3);
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} // namespace openmsx
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#endif