diff --git a/sources/CPU/Cpu.cpp b/sources/CPU/Cpu.cpp
index 680b728..397caba 100644
--- a/sources/CPU/Cpu.cpp
+++ b/sources/CPU/Cpu.cpp
@@ -3,3 +3,10 @@
 //
 
 #include "Cpu.hpp"
+
+namespace ComSquare::CPU
+{
+	CPU::CPU(std::shared_ptr<ComSquare::MemoryBus> bus)
+		: _bus(bus)
+	{ }
+}
\ No newline at end of file
diff --git a/sources/CPU/Cpu.hpp b/sources/CPU/Cpu.hpp
index ebcf8d7..a847226 100644
--- a/sources/CPU/Cpu.hpp
+++ b/sources/CPU/Cpu.hpp
@@ -6,6 +6,7 @@
 #define COMSQUARE_CPU_HPP
 
 #include "../Memory/IMemory.hpp"
+#include "../Memory/MemoryBus.hpp"
 
 namespace ComSquare::CPU
 {
@@ -91,9 +92,22 @@ namespace ComSquare::CPU
 		};
 	};
 
+	//! @brief The main CPU
 	class CPU : IMemory {
 	private:
+		//! @brief All the registers of the CPU
 		Registers _registers;
+		//! @brief Is the CPU running in emulation mode (in 8bits)
+		bool _isEmulationMode;
+		//! @brief The memory bus to use for read/write.
+		std::shared_ptr<MemoryBus> _bus;
+
+		//! @brief Execute a single instruction and return the number of cycles tooked.
+		int executreInstruction();
+	public:
+		explicit CPU(std::shared_ptr<MemoryBus> bus);
+		//! @brief This function continue to execute the Cartridge code and return the number of CPU cycles that elapsed.
+		int update();
 	};
 }