CLK/Machines/Acorn/Archimedes/CMOSRAM.hpp

//
// CMOSRAM.hpp
// Clock Signal
//
// Created by Thomas Harte on 20/03/2024.
// Copyright © 2024 Thomas Harte. All rights reserved.
//

#pragma once

#include "../../../Components/I2C/I2C.hpp"


namespace Archimedes {

struct CMOSRAM: public I2C::Peripheral {
	void start(bool is_read) override {
		expecting_address_ = !is_read;
	}

	std::optional<uint8_t> read() override {
		// VERY TEMPORARY. For now, borrowed from Arcem.
		// To replace with whatever the system-written default is.
		static constexpr uint8_t defaults[] = {
			0x00, 0x83, 0x55, 0x16, 0x14, 0x09, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x03, 0x14, 0x00, 0x6f, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x6d,
			0x01, 0xfe, 0x00, 0xeb, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x10, 0x50, 0x20, 0x08, 0x0a, 0x2c,
			0x80, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x5c, 0x13, 0x00, 0x00, 0x04, 0xfd, 0x08, 0x01, 0xff, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
		};
		static_assert(sizeof(defaults) == 256);

		const uint8_t result = defaults[address_];
		++address_;
		return result;
	}

	bool write(uint8_t value) override {
		if(expecting_address_) {
			address_ = value;
			expecting_address_ = false;
		} else {
			++address_;
			// TODO: write.
		}
		return true;
	}

private:
	bool expecting_address_ = false;
	uint8_t address_;
};

}