Spc_Cpu.h
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Spc_Cpu.h
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	// Super Nintendo (SNES) SPC-700 CPU emulator

	// Game_Music_Emu 0.5.5
	#ifndef SPC_CPU_H
	#define SPC_CPU_H

	#include "blargg_common.h"

	typedef unsigned spc_addr_t;
	typedef blargg_long spc_time_t;

	class Snes_Spc;

	class Spc_Cpu {
	typedef BOOST::uint8_t uint8_t;
	uint8_t* const ram;
	public:
	// Keeps pointer to 64K RAM
	Spc_Cpu( Snes_Spc* spc, uint8_t* ram );

	// SPC-700 registers. Not kept updated during a call to run().
	struct registers_t {
	long pc; // more than 16 bits to allow overflow detection
	uint8_t a;
	uint8_t x;
	uint8_t y;
	uint8_t status;
	uint8_t sp;
	} r;

	// Run CPU for at least 'count' cycles. Return the number of cycles remaining
	// when emulation stopped (negative if extra cycles were emulated). Emulation
	// stops when there are no more remaining cycles or an unhandled instruction
	// is encountered (STOP, SLEEP, and any others not yet implemented). In the
	// latter case, the return value is greater than zero.
	spc_time_t run( spc_time_t count );

	// Number of clock cycles remaining for current run() call
	spc_time_t remain() const;

	// Access memory as the emulated CPU does
	int read ( spc_addr_t );
	void write( spc_addr_t, int );

	private:
	// noncopyable
	Spc_Cpu( const Spc_Cpu& );
	Spc_Cpu& operator = ( const Spc_Cpu& );
	unsigned mem_bit( spc_addr_t );

	spc_time_t remain_;
	Snes_Spc& emu;
	};

	inline spc_time_t Spc_Cpu::remain() const { return remain_; }

	#endif