Memory module and memory system having data protection function, and method for controlling the memory module

A memory system comprising:

• a memory module comprising:
• a memory unit;
• a mode register configured to store a mode identifier;
• a mode memory configured to store mode information including a keyhole mode ID and an access attribute;
• a memory I/F unit configured to receive a key mode ID;
• and
• an access permission unit configured to permit access to the memory unit according to the access attribute when the key mode ID and the keyhole mode ID, corresponding to the mode identifier, are the same;
• an access mode memory configured to store the mode information stored in the mode memory;
• and
• an processor configured to access the memory module while referencing the mode information stored in the access mode memory.

A method for accessing a memory module including a memory unit, comprising:

• storing a mode identifier in a mode register;
• storing mode information including a keyhole mode ID and an access attribute in a mode memory;
• entering a key mode ID in a memory I/F unit;
• and
• permitting access to the memory unit according to the access attribute when the key mode ID and the keyhole mode ID, corresponding to the mode identifier, are the same.