| 摘要 |
PROBLEM TO BE SOLVED: To provide a CRC code arithmetic circuit capable of generating a CRC code by calculating a packet that is parallel signals different in bit length, in relatively small circuit scale.SOLUTION: A CRC code arithmetic circuit 1 comprises: an extraction circuit 10 for extracting an arithmetic object packet subjected to CRC arithmetic from a signal frame that is inputted as parallel signals of a first bit length; a shift circuit 20 which shifts the arithmetic object packet in such a manner that a final bit of the arithmetic object packet is positioned at a least significant bit, and adds "0" at a most significant bit side of bits at a head of the shifted arithmetic object packet, thereby generating data A of which the bit length is an integer multiple of the first bit length; a register 40; and an arithmetic circuit 30 which calculates the data A based on an initial value "0" stored in the register and generates a CRC code of a second bit length. The register 40 stores the initial value "0" before the arithmetic circuit 30 generates the CRC code, and stores the CRC code after the arithmetic circuit 30 generates the CRC code.SELECTED DRAWING: Figure 8 |
