V9990VRAM.cc

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#include "V9990.hh"
#include "V9990VRAM.hh"
#include "serialize.hh"
 
namespace openmsx {
 
V9990VRAM::V9990VRAM(V9990& vdp_, EmuTime::param /*time*/)
        : vdp(vdp_)
        , data(vdp.getDeviceConfig2(), vdp.getName() + " VRAM",
               "V9990 Video RAM", VRAM_SIZE)
{
}
 
void V9990VRAM::clear()
{
        // Initialize memory. Alternate 0x00/0xff every 512 bytes.
        std::span s = data.getWriteBackdoor();
        assert((s.size() % 1024) == 0);
        while (!s.empty()) {
                ranges::fill(s.subspan(  0, 512), 0x00);
                ranges::fill(s.subspan(512, 512), 0xff);
                s = s.subspan(1024);
        }
}
 
unsigned V9990VRAM::mapAddress(unsigned address)
{
        address &= 0x7FFFF; // change to assert?
        switch (vdp.getDisplayMode()) {
        case P1:
                return transformP1(address);
        case P2:
                return transformP2(address);
        default /* Bx */:
                return transformBx(address);
        }
}
 
byte V9990VRAM::readVRAMCPU(unsigned address, EmuTime::param time)
{
        // note: used for both normal and debug read
        sync(time);
        return data[mapAddress(address)];
}
 
void V9990VRAM::writeVRAMCPU(unsigned address, byte value, EmuTime::param time)
{
        sync(time);
        data.write(mapAddress(address), value);
}
 
template<typename Archive>
void V9990VRAM::serialize(Archive& ar, unsigned /*version*/)
{
        ar.serialize("data", data);
}
INSTANTIATE_SERIALIZE_METHODS(V9990VRAM);
 
} // namespace openmsx