CRC ARITHMETIC METHOD AND HEC SYNCHRONIZATION DEVICE IN ATM EXCHANGE SYSTEM

摘要

PURPOSE:To realize the CRC arithmetic operation with a small hardware scale. CONSTITUTION:A CRC arithmetic means 102 executes CRC arithmetic operation to a reception data 101 by using a CRC arithmetic result actual value 103 at a precedence arithmetic operation as an initial value to output the CRC arithmetic result actual value 103. A delay means 104 delays the CRC arithmetic result actual value 103 by a data length of the header part. A CRC arithmetic result introduction means 105 uses the delayed CRC arithmetic result actual value 103 and uses it as an initial value to output the result of arithmetic operation to be possibly obtained if the CRC arithmetic operation were executed to the entire reception data of the header part with the above CRC code added thereto as a CRC arithmetic result derivative value 106. A coincidence detection means 107 compares the CRC arithmetic result actual value 103 with the CRC arithmetic result derivative value 106 to detect an input timing of the header part as the coincident timing of the both.