145 lines
3.0 KiB
C
145 lines
3.0 KiB
C
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#include "Nes_Core.h"
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#include "Nes_Mapper.h"
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#include "blargg_source.h"
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int Nes_Core::cpu_read( nes_addr_t addr, nes_time_t time )
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{
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//LOG_FREQ( "cpu_read", 16, addr >> 12 );
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{
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int result = cpu::low_mem [addr & 0x7FF];
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if ( !(addr & 0xE000) )
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return result;
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}
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{
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int result = *cpu::get_code( addr );
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if ( addr > 0x7FFF )
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return result;
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}
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time += cpu_time_offset;
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if ( addr < 0x4000 )
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return ppu.read( addr, time );
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clock_ = time;
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if ( data_reader_mapped [addr >> page_bits] )
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{
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int result = mapper->read( time, addr );
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if ( result >= 0 )
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return result;
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}
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if ( addr < 0x6000 )
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return read_io( addr );
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if ( addr < sram_readable )
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return impl->sram [addr & (impl_t::sram_size - 1)];
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if ( addr < lrom_readable )
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return *cpu::get_code( addr );
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#ifndef NDEBUG
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log_unmapped( addr );
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#endif
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return addr >> 8; // simulate open bus
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}
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inline int Nes_Core::cpu_read_ppu( nes_addr_t addr, nes_time_t time )
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{
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//LOG_FREQ( "cpu_read_ppu", 16, addr >> 12 );
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// Read of status register (0x2002) is heavily optimized since many games
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// poll it hundreds of times per frame.
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nes_time_t next = ppu_2002_time;
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int result = ppu.r2002;
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if ( addr == 0x2002 )
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{
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ppu.second_write = false;
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if ( time >= next )
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result = ppu.read_2002( time + cpu_time_offset );
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}
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else
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{
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result = cpu::low_mem [addr & 0x7FF];
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if ( addr >= 0x2000 )
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result = cpu_read( addr, time );
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}
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return result;
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}
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void Nes_Core::cpu_write_2007( int data )
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{
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// ppu.write_2007() is inlined
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if ( ppu.write_2007( data ) & Nes_Ppu::vaddr_clock_mask )
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mapper->a12_clocked();
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}
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void Nes_Core::cpu_write( nes_addr_t addr, int data, nes_time_t time )
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{
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//LOG_FREQ( "cpu_write", 16, addr >> 12 );
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if ( !(addr & 0xE000) )
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{
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cpu::low_mem [addr & 0x7FF] = data;
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return;
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}
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time += cpu_time_offset;
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if ( addr < 0x4000 )
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{
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if ( (addr & 7) == 7 )
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cpu_write_2007( data );
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else
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ppu.write( time, addr, data );
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return;
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}
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clock_ = time;
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if ( data_writer_mapped [addr >> page_bits] && mapper->write_intercepted( time, addr, data ) )
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return;
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if ( addr < 0x6000 )
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{
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write_io( addr, data );
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return;
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}
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if ( addr < sram_writable )
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{
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impl->sram [addr & (impl_t::sram_size - 1)] = data;
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return;
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}
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if ( addr > 0x7FFF )
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{
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mapper->write( clock_, addr, data );
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return;
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}
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#ifndef NDEBUG
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log_unmapped( addr, data );
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#endif
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}
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#define NES_CPU_READ_PPU( cpu, addr, time ) \
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STATIC_CAST(Nes_Core&,*cpu).cpu_read_ppu( addr, time )
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#define NES_CPU_READ( cpu, addr, time ) \
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STATIC_CAST(Nes_Core&,*cpu).cpu_read( addr, time )
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#define NES_CPU_WRITEX( cpu, addr, data, time ){\
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STATIC_CAST(Nes_Core&,*cpu).cpu_write( addr, data, time );\
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}
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#define NES_CPU_WRITE( cpu, addr, data, time ){\
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if ( addr < 0x800 ) cpu->low_mem [addr] = data;\
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else if ( addr == 0x2007 ) STATIC_CAST(Nes_Core&,*cpu).cpu_write_2007( data );\
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else STATIC_CAST(Nes_Core&,*cpu).cpu_write( addr, data, time );\
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}
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