The HD74LVCR2245A has eight buffers with three state outputs in a 20 pin package. When (T / R) is high, data flows from the A inputs to the B outputs, and when (T / R) is low, data flows from the B inputs to the A outputs. A and B bus are separated by making enable input (OE) high level. All outputs, which are designed to sink up to 12mA, include equivalent 26 resistors to reduce overshoot and undershoot.