CRC using a Linear Feedback Shift Register

To carry out Cycle Redundacy Checking (CRC) for errors in an electronics circuit I implemented the polynminial X^7 + x^3 +1 in hardware. The circuit comprised a Linear feedback Shift Register (LBSR). It had seven stages with an exclusive OR gate at the input of the first and third stage. The exclusive OR gate at the input to the first stage of the register was used to feedback the output of the last stage The polynomial was implemented by the pattern of the feedforward connections GIN and SR0 to SR5 and feedback connection SR6 together with the position of the exclusive OR gates.