A memory management apparatus uses a link list memory to manage a use area and a vacant area of a data memory. The use of the use area of the data memory by each of plural ports is restricted, and the use area of the data memory is configured to be always provided for each of the plural ports. In this manner, monopolized use of the data memory by a specific port is prevented and each of the plural ports is securely provided with the use area of the data memory under control of the memory management apparatus.