mirror of
https://github.com/ZDoom/gzdoom-gles.git
synced 2024-11-28 15:02:39 +00:00
89 lines
2.1 KiB
C++
89 lines
2.1 KiB
C++
// Z80 CPU emulator
|
|
|
|
// Game_Music_Emu https://bitbucket.org/mpyne/game-music-emu/
|
|
#ifndef AY_CPU_H
|
|
#define AY_CPU_H
|
|
|
|
#include "blargg_endian.h"
|
|
|
|
typedef blargg_long cpu_time_t;
|
|
|
|
// must be defined by caller
|
|
void ay_cpu_out( class Ay_Cpu*, cpu_time_t, unsigned addr, int data );
|
|
int ay_cpu_in( class Ay_Cpu*, unsigned addr );
|
|
|
|
class Ay_Cpu {
|
|
public:
|
|
// Clear all registers and keep pointer to 64K memory passed in
|
|
void reset( void* mem_64k );
|
|
|
|
// 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; }
|
|
|
|
#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)
|
|
|
|
// can read this far past end of memory
|
|
enum { cpu_padding = 0x100 };
|
|
|
|
public:
|
|
Ay_Cpu();
|
|
private:
|
|
uint8_t szpc [0x200];
|
|
uint8_t* mem;
|
|
cpu_time_t end_time_;
|
|
struct state_t {
|
|
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 );
|
|
public:
|
|
registers_t r;
|
|
};
|
|
|
|
inline void Ay_Cpu::set_end_time( cpu_time_t t )
|
|
{
|
|
cpu_time_t delta = state->base - t;
|
|
state->base = t;
|
|
state->time += delta;
|
|
}
|
|
|
|
#endif
|