The 74F402 expandable Serial Data Polynomial generator/ checker is an expandable version of the 74F401. It provides an advanced tool for the implementation of the most widely used error detection scheme in serial digital handling systems. A 4-bit control input selects one-of-six generator polynomials. The list of polynomials includes CRC16, CRC-CCITT and Ethernet, as well as three other standard polynomials (56th order, 48th order, 32nd order). Individual clear and preset inputs are provided for floppy disk and other applications. The Error output indicates whether or not a transmission error has occurred. The CWG Control input inhibits feedback during check word transmission. The 74F402 is compatible with FAST devices and with all TTL families.