Patent ID: 6883129

Claim:
An integrated circuit that is switchable between a normal operating mode and a test mode, the integrated circuit having input contacts, output contacts and a redefinable contact that has an input or output function selected dependent on a circuit configuration, the circuit comprising a functional circuit and a test pattern converter, both coupled between the input contacts, the output contacts and the redefinable contact; the functional circuit and the test pattern converter, in the normal operating mode and the test mode respectively, driving the outputs contacts and, dependent on the circuit configuration, the redefinable contact, the test pattern converter being arranged to provide a first and second relation between signals at the input contacts and the output contacts, with the redefinable contact used as an input or output contact respectively, dependent on the circuit configuration, the relations having been selected so as to permit testing of stuck-at and cross-connect errors with the redefinable contact used as input and output contact respectively.