ZUSAMMENGESETZTE ELEKTRISCHE BAUTEILE

An electrical assembly 1 including a digital logic circuit 10, an analogue processing circuit 11 and an analogue power circuit 12 is connected to test equipment 2. Test data from the equipment 2 is supplied to the circuits 10 to 12 via a shift register 20 divided into three serial portions 21, 22 and 23. One portion 21 is connected between the digital circuit 10 and the processing circuit 11, another portion 22 is connected betwen the processing circuit 11 and the power circuit 12, the final portion 23 being connected at the output of the power circuit 12. The portions 21 and 22 can isolate the circuits from each other and supply test data to the circuit under test. The test data output from the circuit is clocked along the register 20 to its output.