orbum/liborbum/src/Common/Types/Register/MapperHwordWordRegister.hpp

#pragma once

#include <stdexcept>

#include "Common/Types/Primitive.hpp"
#include "Common/Types/Register/WordRegister.hpp"
#include "Common/Types/Register/HwordRegister.hpp"

/// Maps a hword register to word register by zero-filling or truncating.
class MapperHwordWordRegister : public WordRegister
{
public:
	/// Initialise register (initialise underlying register).
	void initialise() override
	{
		hword_register->initialise();
	}

	ubyte read_ubyte(const size_t offset) override
	{
		throw std::runtime_error("Only Word R/W wrapper calls to HwordRegister are allowed.");
	}

	void write_ubyte(const size_t offset, const ubyte value) override
	{
		throw std::runtime_error("Only Word R/W wrapper calls to HwordRegister are allowed.");
	}

	uhword read_uhword(const size_t offset) override
	{
		throw std::runtime_error("Only Word R/W wrapper calls to HwordRegister are allowed.");
	}

	void write_uhword(const size_t offset, const uhword value) override
	{
		throw std::runtime_error("Only Word R/W wrapper calls to HwordRegister are allowed.");
	}

	uword read_uword() override
	{
		return static_cast<uword>(hword_register->read_uhword());
	}

	void write_uword(const uword value) override
	{
		hword_register->write_uhword(static_cast<uhword>(value));
	}

	/// Reference to mapped hword register.
	HwordRegister * hword_register;
};