The M54/74HC620/623 are high speed CMOS OCTAL BUS TRANSCEIVERS fabricated in silicon gate C2MOS technology. They have the same high speed performance of LSTTL combined with true CMOS low power consumption. These octal bus transceivers are designed for asynchronous two-way communication between data buses. The control function implementation allows maximum flexibility in timing. These devices allow data transmission from the A bus to B bus or from the B to the A bus depending upon the logic levels at the enable inputs (GBA and GAB). The enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives these devices the capability to store data by simultaneous enabling of GBA and GAB. Each output reinforces its input.