Abstract: An integrated circuit includes an ECC encoder having a normal mode of operation and a test mode of operation. During the test mode, the encoder is operated as a test pattern generator for computing a test pattern that exhaustively stimulates data paths, memory structures and other logic functions on the integrated circuit. A signature of responses to the test pattern can then be computed and compared to a known "correct" signature to determine whether timing faults and other types of faults exist in the integrated circuit. A disk controller chip based on such an integrated circuit can, in addition to testing its own on-chip data paths, memory structures and other logic functions, supply a test pattern to a read/write channel chip and other components on a printed circuit board assembly of a disk drive.