FIELD: electronics, protection of information in electron circuits with use of scanning network. SUBSTANCE: technical result of invention lies in prevention of unauthorized analysis of circuit arrangement which incorporates several functional units FB1-FBn. Each functional unit is connected to at least another functional unit and some of these connections are realized with the aid of inhibiting element SFF1- SFFm which can be switched from rated mode to testing mode by means of activation bus ( scanning permit ) and which has additional data input and data output. These additional data inputs and data outputs are interconnected with the aid of sections of data bus DL1-DLe so that inhibiting elements SFF1-SFFm form shift register realizing scanning network. At least one electrically programmed protective element SE which either interrupts corresponding conductor or connects it to certain potential is located in activation bus ( scanning permit ) and/or in sections DL1-DLe of data bus. EFFECT: prevention of unauthorized analysis of circuit arrangement. 3 cl, 2 dwg
