58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
|
// Super Nintendo (SNES) SPC-700 CPU emulator
|
||
|
|
|
||
|
|
// Game_Music_Emu 0.5.2
|
||
|
|
#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
|