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qzdoom/game-music-emu/gme/Kss_Cpu.h

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// Z80 CPU emulator
// Game_Music_Emu 0.5.2
#ifndef KSS_CPU_H
#define KSS_CPU_H
#include "blargg_endian.h"
typedef blargg_long cpu_time_t;
// must be defined by caller
void kss_cpu_out( class Kss_Cpu*, cpu_time_t, unsigned addr, int data );
int kss_cpu_in( class Kss_Cpu*, cpu_time_t, unsigned addr );
void kss_cpu_write( class Kss_Cpu*, unsigned addr, int data );
class Kss_Cpu {
public:
typedef BOOST::uint8_t uint8_t;
// Clear registers and map all pages to unmapped
void reset( void* unmapped_write, void const* unmapped_read );
// Map memory. Start and size must be multiple of page_size.
enum { page_size = 0x2000 };
void map_mem( unsigned addr, blargg_ulong size, void* write, void const* read );
// Map address to page
uint8_t* write( unsigned addr );
uint8_t const* read( unsigned addr );
// Run until specified time is reached. Returns true if suspicious/unsupported
// instruction was encountered at any point during run.
bool run( cpu_time_t end_time );
// Time of beginning of next instruction
cpu_time_t time() const { return state->time + state->base; }
// Alter current time. Not supported during run() call.
void set_time( cpu_time_t t ) { state->time = t - state->base; }
void adjust_time( int delta ) { state->time += delta; }
typedef BOOST::uint16_t uint16_t;
#if BLARGG_BIG_ENDIAN
struct regs_t { uint8_t b, c, d, e, h, l, flags, a; };
#else
struct regs_t { uint8_t c, b, e, d, l, h, a, flags; };
#endif
BOOST_STATIC_ASSERT( sizeof (regs_t) == 8 );
struct pairs_t { uint16_t bc, de, hl, fa; };
// Registers are not updated until run() returns
struct registers_t {
uint16_t pc;
uint16_t sp;
uint16_t ix;
uint16_t iy;
union {
regs_t b; // b.b, b.c, b.d, b.e, b.h, b.l, b.flags, b.a
pairs_t w; // w.bc, w.de, w.hl. w.fa
};
union {
regs_t b;
pairs_t w;
} alt;
uint8_t iff1;
uint8_t iff2;
uint8_t r;
uint8_t i;
uint8_t im;
};
//registers_t r; (below for efficiency)
enum { idle_addr = 0xFFFF };
// can read this far past end of a page
enum { cpu_padding = 0x100 };
public:
Kss_Cpu();
enum { page_shift = 13 };
enum { page_count = 0x10000 >> page_shift };
private:
uint8_t szpc [0x200];
cpu_time_t end_time_;
struct state_t {
uint8_t const* read [page_count + 1];
uint8_t * write [page_count + 1];
cpu_time_t base;
cpu_time_t time;
};
state_t* state; // points to state_ or a local copy within run()
state_t state_;
void set_end_time( cpu_time_t t );
void set_page( int i, void* write, void const* read );
public:
registers_t r;
};
#if BLARGG_NONPORTABLE
#define KSS_CPU_PAGE_OFFSET( addr ) (addr)
#else
#define KSS_CPU_PAGE_OFFSET( addr ) ((addr) & (page_size - 1))
#endif
inline BOOST::uint8_t* Kss_Cpu::write( unsigned addr )
{
return state->write [addr >> page_shift] + KSS_CPU_PAGE_OFFSET( addr );
}
inline BOOST::uint8_t const* Kss_Cpu::read( unsigned addr )
{
return state->read [addr >> page_shift] + KSS_CPU_PAGE_OFFSET( addr );
}
inline void Kss_Cpu::set_end_time( cpu_time_t t )
{
cpu_time_t delta = state->base - t;
state->base = t;
state->time += delta;
}
#endif