74HCT245 is an octal transceiver, with in-phase tri-state bus compatible output in both the sending and receiving directions. 4hc245 is a high-speed CMOS bus transceiver compatible with TTL device pins, a typical CMOS three-state buffer gate circuit, and an eight-way signal transceiver. Since the data/address/control bus ports of the microcontroller or CPU have a certain load capacity, if the load exceeds its load capacity, a driver should generally be added.