This 18-bit (dual-octal) noninverting registered transceiver is designed for 1.65-V to 3.6-V V_CC operation.

The SN74ALVCH16901 is a dual 9-bit to dual 9-bit parity transceiver with registers. The device can operate as a feed-through transceiver or it can generate/check parity from the two 8-bit data buses in either direction.

The SN74ALVCH16901 features independent clock (CLKAB or CLKBA), latch-enable (LEAB or LEBA), and dual 9-bit clock-enable (CLKENAB\ or CLKENBA\) inputs. It also provides parity-enable (SEL\) and parity-select (ODD/EVEN\) inputs and separate error-signal (ERRA\ or ERRB\) outputs for checking parity. The direction of data flow is controlled by OEAB\ and OEBA\. When SEL\ is low, the parity functions are enabled. When SEL\ is high, the parity functions are disabled and the device acts as an 18-bit registered transceiver.

To ensure the high-impedance state during power up or power down, OE\ should be tied to V_CC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

The A and B I/Os and APAR and BPAR inputs have bus-hold circuitry. Active bus-hold circuitry holds unused or undriven data inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.