Abstract: A method and apparatus for handling variable data word widths and array depths in an array built-in self-test system for testing a plurality of memory arrays using a single controller. Each array includes a predetermined row and column address depth and data word width. Each array further includes a scan register. A universal test data word is generated and sent to the scan register of each array. The universal length test data word has a length dependent upon the maximum row address depth, maximum column address depth and/or the maximum data word width. A portion of the test data word which exceeds the column address depth, row address depth and/or the data word width of a particular array is shifted off the end of the scan register of the particular array.