Device for testing a circuit comprising sequential and combinatorial logic elements

摘要

A device for processing digital signals includes combinatorial and sequential logic elements. For the testing of the device, a shift register can be formed from the sequential elements. A test pattern is applied thereto. The result of the processing of the test pattern is applied to the shift register. The output of the shift register is connected to a second shift register which forms a moving multibit sum pattern from a received series of result patterns by way of a feedback circuit to at least one Exclusive-OR-element. An output of the feedback circuit is connected to an input of the first shift register in order to apply a subsequent test pattern thereto. After completion of the test, the sum pattern formed is checked.