JPS57152600A - Duplicating system of memory device - Google Patents

Abstract

PURPOSE:To effectively use the storing space and, in the case of multi-processor, and to relief access concentration to one memory unit to improve the throughput of the system, by duplicating only a part of the storing space of the memory device. CONSTITUTION:A memory unit group which is composed of a memory unit MU1 partially containing a normal area H and another memory unit MU2 partially containing a copying area C which duplicates and stores information of the same content as the normal area H, and which can read and write independently, is installed. When a writing request is made to the normal area H, a steering circuit ST sends writing data which is the same as the address, to the memory unit MU2 containing the normal area H and the memory unit MU2 containing the copying area C which corresponds to the normal area H, respectively. Moreover, when an access request other than writing request at normal time is made, the access address and writing data are set only to the memory unit designated by the access address from the outside.