| 摘要 |
PROBLEM TO BE SOLVED: To provide a CRC code arithmetic circuit and a CRC code operating method which suppress the number of used CRC code arithmetic circuits and operate CRC codes from 4n-byte parallel data inputted as variable length data. SOLUTION: This CRC arithmetic circuit 1 for operating the CRC code from parallel data which is inputted as the variable length data and has a remainder part at the last step, is provided with a 4-byte parallel CRC code operating part 3a for parallelly operating the CRC codes from the last step of the parallel data, a SEL 3e for selecting CRC codes for the prescribed number of bytes from the operated CRC codes, a 4-byte serial conversion circuit 5 for converting the last step of the parallel data into serial data, and a one-byte parallel CRC code operating part 4a for operating the CRC codes from the CRC codes selected by the SEL 3e and the serial data converted by the conversion circuit 5. |
