Semiconductor memory apparatus, memory access control system and data reading method

A memory access control system which reads data from a semiconductor memory apparatus via a memory access control circuit, wherein the memory access control circuit inputs a read request including:

• address information which is referred to when the data is read from the semiconductor memory apparatus;
• priority information which indicates priority of reading the data;
• and storing area identification information which is used for determining a storing area of the read data while maintaining a corresponding relationship thereof, and comprises a read request transport portion which outputs the read request that has been input,
• the semiconductor memory apparatus comprises:
• a main memory which stores data at an address while maintaining a corresponding relationship between the data and the address;
• a read data storing portion which stores the data, priority, and storing area identification information while maintaining a corresponding relationship thereof;
• a read request input portion receiving a read request from the memory access control circuit;
• a data reading portion reads the data corresponding to address information included in the read request which is input by the read request input portion from the main memory;
• a read data registration portion storing the priority information input by the read request input portion, the data read by the data reading portion and the storing area identification information to the read data storing portion while maintaining a corresponding relationship thereof;
• and
• a priority operation control portion which chooses the data and the storing area identification information with a highest priority among the data, the priority and the storing area identification information stored in the read data storing portion and outputs the data and the storing area identification information to the memory access control portion while maintaining a corresponding relationship thereof, and
• the memory access control circuit comprises a data storing portion which inputs the data and the storing area identification information from the semiconductor memory apparatus while maintaining a corresponding relationship thereof and stores the data based on the storing area identification information.

A data reading method of a semiconductor memory apparatus which includes a main memory that stores data while maintaining a corresponding relationship between the data and an address, comprising:

• a step of inputting a read request including both address information which is referred to when reading the data and priority information which indicates priority for reading the data while maintaining a corresponding relationship thereof;
• a step of reading the data corresponding to the address information from the main memory;
• a step of storing the read data and the priority information at a read data memory portion which stores the data and the priority information while maintaining a corresponding relationship thereof;
• and
• a step of choosing the data with a highest priority among the data and the priority information stored in the read data memory portion, and outputting the chosen data.