The 'ACT16474 are noninverting 18-bit registered bus transceivers composed of two 9-bit sections with separate control signals. For either 9-bit transceiver section, data flow in the A-to-B mode is controlled by output-enable (1OEAB or 2OEAB) and clock (1CLKAB or 2CLKAB) inputs. When 1OEAB or 2OEAB is low, the corresponding outputs are active (high or low) and take on either the current data on low-to-high transition of 1CLKAB or 2CLKAB or the previously stored data if 1CLKAB or 2CLKAB is low.