CONTROLLER AND INTEGRATED CIRCUIT FOR REALIZING SCANNING TEST

摘要

PROBLEM TO BE SOLVED: To obtain a TAP controller which can execute any one of structural test or function test through minimum modification of a controller executing the structural test. SOLUTION: An instruction register 520 in a TAP controller 12 loads an instruction register 520 with an instruction related to structural best or function test. A multiplexer 518 is switched by receiving an output signal PERFSELECT from the instruction register 520 to select the set of first gate LGI realizing the structural test or the set of second logic gate LG2 realizing the function test. The selected set then translates each state of a state machine and a TAP control signal on a selected line 509 is fed to a clock generator 510 thus generating a signal COMMONCLK adaptable to the test.