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