wf1988：
SN74HC244DWRSN74HC244(ACTIVE)具有三態輸出的八路緩沖器和線路驅動器Theseoctalbuffersandlinedriversaredesignedspecificallytoimproveboththeperformanceanddensityof3-statememoryaddressdrivers,clockdrivers,andbus-orientedreceiversandtransmitters.The’HC244devicesareorganizedastwo4-bitbuffers/driverswithseparateoutput-enable(OE)\inputs.WhenOE\islow,thedevicepassesnoninverteddatafromtheAinputstotheYoutputs.WhenOE\ishigh,theoutputsareinthehigh-impedancestate.74HC244芯片內部共有兩個四位三態緩沖器，使用時可分別以1G和2G作為它們的選通工作信號.當1G和2G都為低電平時，輸出端Y和輸入端A狀態相同；當1G和2G都為高電平時，輸出呈高阻態.