Abstract: A test data generator and a test data converter are provided for generating test data words which are allocated to the terminal elements of a card module having electronic components. Dependent on a test program, the test data generator generates one or more test data vectors per test step to be executed. The test data converter generates the test data words from a test data vector or from further test information, and allocates individual bits of a test vector or of the test information to individual terminal elements of the unit under test. The allocation of the individual bits of the test vector or of the test information to the individual terminal elements of the unit under test can be freely set.

Abstract: When testing a unit under test, for example, a card module, check characters must be transmitted to the unit under test from the tester via connector elements. One selection device per connector element is provided in order to be able to transmit the correct check character over the correct connector element. Each selection device contains addresses of the check characters which are to be transmitted over the allocated connector element in an address register. During the test event, the assistance of a comparison device is employed in order to determine whether the addresses contained in the address register coincide with the addresses of check characters which are supplied by an input bus. Given equality, the allocated test signal is transmitted to the connector element. When a plurlity of check characters are allocated to one address, one of the check characters can be selected and transmitted to the connector element with the assistance of a multiplexer given equality of the addresses.