| 摘要 |
In order to shorten the processing time for partially rewrite the data of a SAM array with data of a RAM array without rewriting the content held in the RAM array, and to elevate the integration density, a read transfer gate 11 is added with a mask control function, and there is also added a function of fetching a read mask data SMDr into a serial mask register 13 and of supplying the read mask data SMDr to the read transfer gate 11. The mask data is fetched from an external to the serial mask register 13 through a random data input/output port Prdt, and the control for fetching the mask data is executed on the basis of a serial data latch timing signal SMLT generated in a timing generator 14 on the basis of a row address strobe signal. Thus, the partial data rewriting of the data in the SAM array 8 can be executed in one data transfer cycle.
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