Circuit for testing circuit blocks controlled by microinstructions

摘要

A test circuit for testing circuit blocks of an integrated circuit device controlled with microinstructions comprising a microinstruction register (13). The microinstruction register (13) is basically the one originally provided in the integrated circuit device but it holds not only a microinstruction read out of a micro-ROM (12) but also a control signal that is set externally to set the circuit blocks of the integrated circuit device. The control signal set externally in the microinstruction register (13) is decoded by a microdecoder (14) to test operation of the circuit blocks.