Apparatus for performing a cyclic redundancy code check on a binary digital
signal consisting of a variable multiplicity (M) of data bytes comprises a
buffer register for temporarily storing in succession segments each
consisting of an integral number (N) of bytes. Each successive segment is
loaded into a cyclic redundancy checker which produces a remainder after
performing polynomial division of the digital signal. When the number of
bytes of the digital signal in the last segment is less than the integral
plurality (N) that last segment is padded with constant data. The signal
is deemed valid if the remainder matches any of a plurality of
predetermined remainders each corresponding to the operation of the
checker on a valid digital signal padded with zero to (N-1) bytes of the
constant data
