SN74LS640 Description
SN74LS640, SN74LS641, SN74LS642, SN74LS645 Octal Bus Transceivers These octal bus transceivers are designed for asynchronous two-way munication between data buses. Control function implementation minimizes external timing requirements. These circuits allow data transmission from the A bus to B or from the B bus to A bus depending upon the logic level of the direction control (DIR) input.