nes_cpu_io.h

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#include "Nsf_Emu.h"
 
#if !NSF_EMU_APU_ONLY
        #include "Nes_Namco_Apu.h"
#endif
 
#include "blargg_source.h"
 
int Nsf_Emu::cpu_read( nes_addr_t addr )
{
        int result;
        
        result = cpu::low_mem [addr & 0x7FF];
        if ( !(addr & 0xE000) )
                goto exit;
        
        result = *cpu::get_code( addr );
        if ( addr > 0x7FFF )
                goto exit;
        
        result = sram [addr & (sizeof sram - 1)];
        if ( addr > 0x5FFF )
                goto exit;
        
        if ( addr == Nes_Apu::status_addr )
                return apu.read_status( cpu::time() );
        
        #if !NSF_EMU_APU_ONLY
                if ( addr == Nes_Namco_Apu::data_reg_addr && namco )
                        return namco->read_data();
        #endif
        
        result = addr >> 8; // simulate open bus
        
        if ( addr != 0x2002 )
                debug_printf( "Read unmapped $%.4X\n", (unsigned) addr );
        
exit:
        return result;
}
 
void Nsf_Emu::cpu_write( nes_addr_t addr, int data )
{
        {
                nes_addr_t offset = addr ^ sram_addr;
                if ( offset < sizeof sram )
                {
                        sram [offset] = data;
                        return;
                }
        }
        {
                int temp = addr & 0x7FF;
                if ( !(addr & 0xE000) )
                {
                        cpu::low_mem [temp] = data;
                        return;
                }
        }
        
        if ( unsigned (addr - Nes_Apu::start_addr) <= Nes_Apu::end_addr - Nes_Apu::start_addr )
        {
                GME_APU_HOOK( this, addr - Nes_Apu::start_addr, data );
                apu.write_register( cpu::time(), addr, data );
                return;
        }
        
        unsigned bank = addr - bank_select_addr;
        if ( bank < bank_count )
        {
                blargg_long offset = rom.mask_addr( data * (blargg_long) bank_size );
                if ( offset >= rom.size() )
                        set_warning( "Invalid bank" );
                cpu::map_code( (bank + 8) * bank_size, bank_size, rom.at_addr( offset ) );
                return;
        }
        
        cpu_write_misc( addr, data );
}
 
#define CPU_READ( cpu, addr, time )         STATIC_CAST(Nsf_Emu&,*cpu).cpu_read( addr )
#define CPU_WRITE( cpu, addr, data, time )  STATIC_CAST(Nsf_Emu&,*cpu).cpu_write( addr, data )