A word of a test pattern is divided into blocks and stored in a storage device of a test pattern generator for testing a logic device. The test pattern blocks are sequentially provided to respective blocks of a pattern generator, which provides at respective outputs all of the blocks of a test pattern word at the same time. If a block of the pattern generator is faulty, or if another component of the test pattern generator corresponding to a block of the pattern generator is faulty, the respective block of each test pattern word can be provided to an unused block of the pattern generator, for providing the test patterns for testing the logic device without the need for reprogramming the test pattern blocks to be stored in the storage device. The data stored in the storage device identifies the position of each respective block of the test pattern words, for controlling the transferring of the test pattern blocks from the storage device to the pattern generator.