| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique which reduces the cost of a memory module provided with a parity function. SOLUTION: In accordance with plural data mask signal terminals DQM 0-DQM3, installed in correspondence with data input/output terminals I/O 0-I/O 3 and the logic of the signals given to individual data mask terminals from outside, a SDRAM(Synchronous Dynamic Random Access Memory) is formed, including input control circuits 700-703 and output control circuits 800-803 which allow to control the data input/output from the corresponding data input/output terminals. Such a SDRAM is used as the one exclusively for parity and other inexpensive SDRAMs having no parity function are applied in plural numbers, thereby reducing the cost of memory modules. |
