Ever needed to interface a 3.3V device from a 5V microcontroller circuit? This device makes it a lot easier.
The SN74LVC245A has an A and B bus, both 8 bits wide. It can transmit from bus A to B or from B to A, depending on the state of the DIR pin. The input side can accept anything up to 5.5V and the output high level matches VCC supplied to the IC.