Semiconductor memory device capable of controlling tac timing and method for operating the same

Abstract

A semiconductor memory device is capable of controlling a tAC with a timing margin in an output data process. The semiconductor memory device includes a delay locked loop circuit, a tAC control unit, a reference signal generating unit, and a data output block. The delay locked loop circuit produces delay locked clock signals through a delay locking operation. The tAC control unit adjusts a delay value of the delay locked clock signals in order to control a tAC timing, thereby generating output reference signals. The reference signal generating unit produces a latch reference signal in response to the delay locked clock signals. The data output block latches data in response to the latch reference signal and for outputting the latched data in response to the output reference signals.