JPS6469975A - Logic operation circuit package - Google Patents

Abstract

PURPOSE:To enable the execution of a detailed pseudo fault in a short verification time on the basis of a pseudo fault diagnosis information, by providing a decoder decoding the information inputted from outside, a hold circuit storing an output of the decoder temporarily and a logical product circuit outputting the logical product of a part of an input signal of a logic operation circuit and an output signal of the hold circuit. CONSTITUTION:A pseudo-fault diagnosis input signal 10 impressed from an external control unit is impressed on a decoder circuit 9, and a pseudo fault signal 8 for a desired corresponding position (either one of input signals 2-2) is outputted by this circuit. The signal 8 is inputted to a hold circuit 7 conducting temporary storage, and an output 6 thereof is held and then impressed on each corresponding logical product circuit 3. When a package 11 including a logic operation circuit 1 is made to execute a testing diagnosis of various fault detecting circuits provided in the circuit 1 and when each diagnostic program prepared for a fault of the circuit 1 is executed or verified, according to this constitution, the setting of a pseudo fault for the package 11 is enabled by impressing the desired signal 10 from the external control unit under the condition that the circuit 1 executes an ordinary operation.