Memory system and computer system

Abstract

When a memory card is inserted into a computer, a memory controller sends command information stored in a memory array to the computer. Then, the computer stores the command information received from the memory card into a RAM. The computer generates a command as needed on the basis of the stored command information and sends the generated command to the memory card. When the memory card receives the command from the computer, the memory controller analyzes the received command and performs it while making reference to command analysis information. This makes it possible to reduce a load accompanying the change and addition of commands in a semiconductor memory.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a technique to reduce a load accompanying the change of specifications of a semiconductor memory.[0003]2. Description of the Background Art[0004]In nonvolatile semiconductor memories in which game data and the like are stored, commands are inputted from external systems and various operations, such as reading of data from desired addresses, deletion of desired blocks, writing of data into desired pages or the like, are performed in response to the commands.[0005](Patent Document 1) Japanese Patent Application Laid Open Gazette No. 2001-283170.[0006]Taking, e.g., game cassettes used for game devices as an example of semiconductor memories, commands encrypted in the system are generally used in order to prevent an illegal copy of game software. But if the encrypted commands are decoded, the specifications of the semiconductor memory have to be changed as soon as possible.[0007]In the conve...

AI Technical Summary

Benefits of technology

[0011]By the memory system of present invention, it becomes possible to change and add commands only by rewriting the command information and the command analysis information without changing any hardware. Therefore, a development load of changing specifications of the memory system can be reduced.

[0016]By these aspects of the present invention, it is possible to increase the speed of command analysis operation.

[0019]It thereby becomes unnecessary to change the constitution of the computer even if the specifications of the memory system is changed. It is further unnecessary to change the hardware of the memory system. Therefore, a development load of changing specifications of the memory system can be reduced.

[0021]It is therefore an object of the present invention to reduce a load accompanying the change and addition of commands in a semiconductor memory.

Problems solved by technology

In the conventional semiconductor memories, however, combinations of the commands and operations are fixed to each of the semiconductor memories and if the commands are changed or added, redesign of the whole semiconductor memory is disadvantageously needed.

Further, if the specifications of the semiconductor memory is changed, the external system (e.g., a game device or the like) using it has to respond to the change, and this requires more costs.