The 'LVT16543 are 16-bit registered transceivers designed for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. Separate latch-enable (LEAB or LEBA) and output-enable (OEAB or OEBA) inputs are provided for each register to permit independent control in either direction of data flow. The A-to-B enable (CEAB) input must be low in order to enter data from A or to output data from B. If CEAB is low and LEAB is low, the A-to-B latches are transparent; a subsequent low-to-high transition of LEAB puts the A latches in the storage mode. With CEAB and OEAB both low, the 3-state B outputs are active and reflect the data present at the output of the A latches. Data flow from B to A is similar but requires using the CEBA, LEBA, and OEBA inputs.