ANovelMethodofTestGeneration forAsynchronous Circuits

Designofasynchronous circuits involves primitive structures whichhavelocal feedback loops like C-elements. Due II. Background tothepresence ofnumberofsuchprimitive elements, theloops in asynchronous circuits arehigh. Increased numberofloopsin thesecyclic asynchronous circuits makestheconventional thesecyclicasynchronous CDtosofilcuas tkey arecalenional Inthispaper, forcyclic toacyclic conversion, a circuit is synchronous Ac circuits Thisas the generation oftestrepresented bya Circuit Topology graph (CTG), wherethe nodesofthegraph formthegates inthecircuit andthearcs patterns forasynchronous circuits a hardtask.Thispaper focuses on thisproblem anddealswiththetestgeneration formtheconnection between thegates. Cyclic structures occur processinvolving theconversion of cyclic asynchronous inasynchronous circuits more often duetothepresence of structures toequivalent acyclic structures before generating testlocal andglobal loops. Acyclic circuits arecircuits comprising andthereby improving thefault coverage. Thus,enabling thetestonly offeedforward paths, wheretheoutput ofonegate isfed generation forthese circuits andincreasing thefault coverage, totheinput ofthenextgate andsoon.Cyclic circuits arethe circuits comprising ofbothfeedforward andfeedback paths. Inthese circuits, either theoutput ofthegateisfedbacktoits IIntroduction input ortheoutput ofother gateintheforward pathisfedto itsinput. Theformer caseiscalled local loopandthelater is Testgeneration methods forasynchronous circuits areless called global loop. investigated compared tothat ofsynchronous circuits. DuetoI theabsence ofglobal clocks inthecircuit, several problems arise whengenerating test patterns forasynchronous circuits. Te cTGlof anasyctou circut w ontcycles.