bsnes/higan/gb/cartridge/mbc7/mbc7.hpp

struct MBC7 : Mapper {
  enum : uint { Center = 0x81d0 };  //not 0x8000

  //mbc7.cpp
  auto load(Markup::Node document) -> void override;
  auto save(Markup::Node document) -> void override;
  auto main() -> void override;
  auto read(uint16 address) -> uint8 override;
  auto write(uint16 address, uint8 data) -> void override;
  auto power() -> void override;

  //serialization.cpp
  auto serialize(serializer&) -> void override;

  struct EEPROM {
    //eeprom.cpp
    auto load(Markup::Node document) -> void;
    auto save(Markup::Node document) -> void;
    auto main() -> void;
    auto power() -> void;

    //Game Boy MBC7 interface
    auto readIO() -> uint8;
    auto writeIO(uint8 data) -> void;

    //chip commands
    auto read() -> void;
    auto write() -> void;
    auto erase() -> void;
    auto writeAll() -> void;
    auto eraseAll() -> void;
    auto writeEnable() -> void;
    auto writeDisable() -> void;

    //serialization.cpp
    auto serialize(serializer&) -> void;

    //it is awkward no matter if data is uint1[4096], uint8[512], or uint16[256]
    uint8 data[512];   //uint8 was chosen solely for easier serialization and saving
    uint size;         //in bytes
    uint width;        //8-bit (ORG=0) or 16-bit (ORG=1) configuration

    boolean select;    //CS
    boolean clock;     //CLK
    boolean writable;  //EWEN, EWDS
    uint busy;         //busy cycles in milliseconds remaining for programming (write) operations to complete

    struct ShiftRegister {
      auto flush() -> void;
      auto edge() -> uint1;
      auto read() -> uint1;
      auto write(uint1 data) -> void;

      uint32 value;
      uint32 count;
    };

    struct InputShiftRegister : ShiftRegister {
      auto start() -> maybe<uint1>;
      auto opcode() -> maybe<uint2>;
      auto mode() -> maybe<uint2>;
      auto address() -> maybe<uint9>;
      auto data() -> maybe<uint16>;
      auto increment() -> void;

      //serialization.cpp
      auto serialize(serializer&) -> void;

      uint32 addressLength;
      uint32 dataLength;
    } input;

    struct OutputShiftRegister : ShiftRegister {
      //serialization.cpp
      auto serialize(serializer&) -> void;
    } output;
  } eeprom;

  struct IO {
    struct ROM {
      uint8 bank = 0x01;
    } rom;
    struct RAM {
      uint1 enable[2];
    } ram;
    struct Accelerometer {
      uint16 x = Center;
      uint16 y = Center;
    } accelerometer;
  } io;
} mbc7;