Abstract: Disclosed is a circuit for implementing a special mode in a packet-based semiconductor memory device, which performs the special mode in the same manner as a normal operation without changing the semiconductor memory devie from a special mode register to a control register mode prior to a normal operation or at the middle of the normal operation after an initial operation having a reset operation. A packet receiving part receives external packet data. A register controller generates a control signal to select a special mode register according to a value of a first field among the external packet data received by the packet receiving part. A register value generator generates a value of the special mode register selected by the control signal from the register controller according to a value of a second field among the received external packet data when the register controller generates the control signal.

Abstract: Disclosed is a Rambus DRAM capable of reducing power consumption and layout area by enabling data read/write control signal of accessed memory bank only, in a top memory bank and a bottom memory bank. The disclosed comprises: a top and a bottom memory bank blocks including a plurality of unit memory banks, respectively; and a data read/write control signal generation block for generating a top data write control signal and a top data read control signal to the top memory bank block and a bottom data write control signal and a bottom data read control signal to the bottom memory bank block, thereby controlling the top memory bank block and the bottom memory bank block to separately operate in data read/write operations.

Abstract: A semiconductor memory device using a protocol transmission method, having an improved packet structure comprises a plurality of banks having N subregions which are simultaneously accessed by activation of one row, and a memory control unit capable of accessing a predetermined subregion of the N subregions according to a predetermined field value of packet.

Abstract: A clock control circuit for a Rambus DRAM is provided which reduces power consumption by determining in advance whether an applied command is a read or current control command, and enabling a clock signal for externally outputting an internal data only during the read or current control command.