Access control unit and method for use with synchronous dynamic random access memory device

摘要

An access control unit and method is proposed for use with an SDRAM (Synchronous Dynamic Random-Access Memory) device to control each round of burst-transfer type of access operation on the SDRAM device. The proposed access control unit and method is characterized by that the column-address strobe signal involved in each round of the burst-transfer access operation is continuously set at active state for a period of clock pulses equal in number to the specified burst length of the burst-transfer access operation, rather than just for a period of one pulse. This feature allows external circuitry to arbitrarily change the burst length, and also allows no use of burst-stop command or a precharge-interrupt method to stop each round of the burst-transfer access operation, allowing the access control logic circuit architecture to be more simplified than the prior art.