Abstract: A system for detecting an initialization flag signal and distinguishing it from a normal flag signal having half the duration of the initialization flag signal. The initialization flag detection system may be included in the command buffer of a packetized DRAM that is used in a computer system. In one embodiment, the initialization flag detection system includes a pair of shift registers receiving the flag signal at their respective data inputs. One of the shift registers is clocked by a signal corresponding to an externally applied to command clock signal, while the other shift register is clocked by a quadrature clock signal. Together, the shift registers store a number of samples taken over a duration that is longer than the duration of the normal flag signal. The outputs of the shift registers are applied to a logic circuit, such as a NAND gate, that generates an initialization signal when all of the samples stored in the shift registers correspond to the logic levels of the flag signal.