16-bit bus transceiver and transparant D-type latch with 8 independent buffers

The 74ALVCH32973 is a 16-bit bus transceiver and transparent D-type latch with 8 independent buffers with bus hold inputs and 3-state outputs. It features direction (1DIR, 2DIR), latch enable (1LOE, 2LOE), transceiver output enable (1TOE, 2TOE) and latch enable (1LE, 2LE) control inputs; four 8-bit transceiver ports (1An, 2An & 1Bn, 2Bn); two 8-bit D-type latch output ports (1Qn, 2Qn) and an 8-bit buffer with data inputs Dn and outputs Yn. The configuration of the control pins allows the device to be used as one 8-bit buffer, two 8-bit transceivers, and two 8-bit latches or one 8-bit buffer, one 16-bit transceiver and one 16-bit latch.

The 8-bit buffer functions independently of the control inputs. The direction of data transmission between A and B is controlled by nDIR and when nTOE is set HIGH the A and B ports will assume a HIGH-impedance OFF-state, they will be effectively isolated. When nLE is HIGH, data at the A inputs enter the latches. In this condition the latches are transparent, a Q output will change each time its corresponding A-input changes. When nLE is LOW the latches store the information that was present at the inputs a set-up time preceding the HIGH-to-LOW transition of nLE. A HIGH on nLOE causes the Q outputs to assume a high-impedance OFF-state. Operation of the nLOE input does not affect the state of the latches.