These 8-bit D-type transparent latches are designed specifically for storing the contents of the input data bus, plus reading back the stored data onto the input data bus. In addition, they provide a 3-state buffer-type output and are easily utilized in bus-structured applications. While the latch enable (LE) is high, the Q outputs of the SN74ALS666 follow the data (D) inputs. The Q outputs of the SN74ALS667 provide the inverse of the data applied to its D inputs. The Q or Q output of both devices is in the high-impedance state if either output-enable (OE1 or OE2) input is at a high logic level.