MAIN STORAGE DEVICE USING DATA STORAGE PROTOCOL

摘要

PROBLEM TO BE SOLVED: To perform read of a double data rate(DDR) DRAM at a data transfer rate being higher than that of the entire existing circuits which are using a strobe and a data protocol by realizing a circuit with mitigated relation between the strobe and a data eye and also a protocol. SOLUTION: A strobe generator 149 connected to both of a data input and a strobe input is added in order to control the multiple latch circuit 33 of a write circuit 118 so that a write circuit of conventional technique is changed. An initializing and validating circuit is connected and also a data comparing circuit which is connected between a storage array 21 and a toggle circuit is added in order to control the strobe so that a read circuit of conventional technique is changed. The strobe for reading/writing is generated only when a data state transition does not exist so that it is made unnecessary to perform positioning of the strobe and the data eye.