MSXPPI.cc

Go to the documentation of this file.

#include "MSXPPI.hh"
#include "LedStatus.hh"
#include "MSXCPUInterface.hh"
#include "MSXMotherBoard.hh"
#include "Reactor.hh"
#include "CassettePort.hh"
#include "RenShaTurbo.hh"
#include "GlobalSettings.hh"
#include "serialize.hh"
 
namespace openmsx {
 
MSXPPI::MSXPPI(const DeviceConfig& config)
        : MSXDevice(config)
        , cassettePort(getMotherBoard().getCassettePort())
        , renshaTurbo(getMotherBoard().getRenShaTurbo())
        , i8255(*this, getCurrentTime(), config.getGlobalSettings().getInvalidPpiModeSetting())
        , click(config)
        , keyboard(
                config.getMotherBoard(),
                config.getMotherBoard().getScheduler(),
                config.getMotherBoard().getCommandController(),
                config.getMotherBoard().getReactor().getEventDistributor(),
                config.getMotherBoard().getMSXEventDistributor(),
                config.getMotherBoard().getStateChangeDistributor(),
                Keyboard::MATRIX_MSX, config)
{
        reset(getCurrentTime());
}
 
MSXPPI::~MSXPPI()
{
        powerDown(EmuTime::dummy());
}
 
const Keyboard& MSXPPI::getKeyboard() const {
        return keyboard;
}
 
void MSXPPI::reset(EmuTime::param time)
{
        i8255.reset(time);
        click.reset(time);
}
 
void MSXPPI::powerDown(EmuTime::param /*time*/)
{
        getLedStatus().setLed(LedStatus::CAPS, false);
}
 
byte MSXPPI::readIO(word port, EmuTime::param time)
{
        return i8255.read(port & 0x03, time);
}
 
byte MSXPPI::peekIO(word port, EmuTime::param time) const
{
        return i8255.peek(port & 0x03, time);
}
 
void MSXPPI::writeIO(word port, byte value, EmuTime::param time)
{
        i8255.write(port & 0x03, value, time);
}
 
 
// I8255Interface
 
byte MSXPPI::readA(EmuTime::param time)
{
        return peekA(time);
}
byte MSXPPI::peekA(EmuTime::param /*time*/) const
{
        // port A is normally an output on MSX, reading from an output port
        // is handled internally in the 8255
        // TODO check this on a real MSX
        // TODO returning 0 fixes the 'get_selected_slot' script right after
        //      reset (when PPI directions are not yet set). For now this
        //      solution is good enough.
        return 0;
}
void MSXPPI::writeA(byte value, EmuTime::param /*time*/)
{
        getCPUInterface().setPrimarySlots(value);
}
 
byte MSXPPI::readB(EmuTime::param time)
{
        return peekB(time);
}
byte MSXPPI::peekB(EmuTime::param time) const
{
        auto& keyb = const_cast<Keyboard&>(keyboard);
        if (selectedRow != 8) {
                return keyb.getKeys()[selectedRow];
        } else {
                return keyb.getKeys()[8] | (renshaTurbo.getSignal(time) ? 1:0);
        }
}
void MSXPPI::writeB(byte /*value*/, EmuTime::param /*time*/)
{
        // probably nothing happens on a real MSX
}
 
nibble MSXPPI::readC1(EmuTime::param time)
{
        return peekC1(time);
}
nibble MSXPPI::peekC1(EmuTime::param /*time*/) const
{
        return 15; // TODO check this
}
nibble MSXPPI::readC0(EmuTime::param time)
{
        return peekC0(time);
}
nibble MSXPPI::peekC0(EmuTime::param /*time*/) const
{
        return 15; // TODO check this
}
void MSXPPI::writeC1(nibble value, EmuTime::param time)
{
        if ((prevBits ^ value) & 1) {
                cassettePort.setMotor((value & 1) == 0, time); // 0=0n, 1=Off
        }
        if ((prevBits ^ value) & 2) {
                cassettePort.cassetteOut((value & 2) != 0, time);
        }
        if ((prevBits ^ value) & 4) {
                getLedStatus().setLed(LedStatus::CAPS, (value & 4) == 0);
        }
        if ((prevBits ^ value) & 8) {
                click.setClick((value & 8) != 0, time);
        }
        prevBits = value;
}
void MSXPPI::writeC0(nibble value, EmuTime::param /*time*/)
{
        selectedRow = value;
}
 
 
template<typename Archive>
void MSXPPI::serialize(Archive& ar, unsigned /*version*/)
{
        ar.template serializeBase<MSXDevice>(*this);
        ar.serialize("i8255", i8255);
 
        // merge prevBits and selectedRow into one byte
        auto portC = byte((prevBits << 4) | (selectedRow << 0));
        ar.serialize("portC", portC);
        if constexpr (Archive::IS_LOADER) {
                selectedRow = (portC >> 0) & 0xF;
                nibble bits = (portC >> 4) & 0xF;
                writeC1(bits, getCurrentTime());
        }
        ar.serialize("keyboard", keyboard);
}
INSTANTIATE_SERIALIZE_METHODS(MSXPPI);
REGISTER_MSXDEVICE(MSXPPI, "PPI");
 
} // namespace openmsx