gb_cpu_io.h

Go to the documentation of this file.

 
#include "Gbs_Emu.h"
 
#include "blargg_source.h"
 
int Gbs_Emu::cpu_read( gb_addr_t addr )
{
        int result = *cpu::get_code( addr );
        if ( unsigned (addr - Gb_Apu::start_addr) < Gb_Apu::register_count )
                result = apu.read_register( clock(), addr );
#ifndef NDEBUG
        else if ( unsigned (addr - 0x8000) < 0x2000 || unsigned (addr - 0xE000) < 0x1F00 )
                debug_printf( "Read from unmapped memory $%.4x\n", (unsigned) addr );
        else if ( unsigned (addr - 0xFF01) < 0xFF80 - 0xFF01 )
                debug_printf( "Unhandled I/O read 0x%4X\n", (unsigned) addr );
#endif
        return result;
}
 
void Gbs_Emu::cpu_write( gb_addr_t addr, int data )
{
        unsigned offset = addr - ram_addr;
        if ( offset <= 0xFFFF - ram_addr )
        {
                ram [offset] = data;
                if ( (addr ^ 0xE000) <= 0x1F80 - 1 )
                {
                        if ( unsigned (addr - Gb_Apu::start_addr) < Gb_Apu::register_count )
                        {
                                GME_APU_HOOK( this, addr - Gb_Apu::start_addr, data );
                                apu.write_register( clock(), addr, data );
                        }
                        else if ( (addr ^ 0xFF06) < 2 )
                                update_timer();
                        else if ( addr == joypad_addr )
                                ram [offset] = 0; // keep joypad return value 0
                        else
                                ram [offset] = 0xFF;
 
                        //if ( addr == 0xFFFF )
                        //  debug_printf( "Wrote interrupt mask\n" );
                }
        }
        else if ( (addr ^ 0x2000) <= 0x2000 - 1 )
        {
                set_bank( data );
        }
#ifndef NDEBUG
        else if ( unsigned (addr - 0x8000) < 0x2000 || unsigned (addr - 0xE000) < 0x1F00 )
        {
                debug_printf( "Wrote to unmapped memory $%.4x\n", (unsigned) addr );
        }
#endif
}
 
#define CPU_READ_FAST( cpu, addr, time, out ) \
        CPU_READ_FAST_( STATIC_CAST(Gbs_Emu*,cpu), addr, time, out )
 
#define CPU_READ_FAST_( emu, addr, time, out ) \
{\
        out = READ_PROG( addr );\
        if ( unsigned (addr - Gb_Apu::start_addr) < Gb_Apu::register_count )\
                out = emu->apu.read_register( emu->cpu_time - time * clocks_per_instr, addr );\
        else\
                check( out == emu->cpu_read( addr ) );\
}
 
#define CPU_READ( cpu, addr, time ) \
        STATIC_CAST(Gbs_Emu*,cpu)->cpu_read( addr )
 
#define CPU_WRITE( cpu, addr, data, time ) \
        STATIC_CAST(Gbs_Emu*,cpu)->cpu_write( addr, data )