| 摘要 |
PURPOSE:To extract exactly an additional information synchronizing signal by a comparatively simple circuit and to realize a transmitting system having a high transmission efficiency, by discriminating the generatin of CRCC in a main data block to which head information of a sub-data block is added. CONSTITUTION:Two kinds of CRCC operators 12 (initial value all ''0'') and 13 (initial value all ''1'') corresponding to different initial values in case of generation of CRCC are provided and execute an operation of CRCC in parallel to a transmitting data. In case when an error occurs in a transmitting system in which a result of the CRCC operation is O.K. and ''1'', both outputs of the operators 12, 13 become ''0'', and in case when additional information is at the head of a sub-data block and there is no error in the transmitting system, the outputs of the operators 12, 13 become ''0'' and ''1'', and in case when the additional information is on the way of the sub-data block and there is no error in the transmitting system, the outputs of the operators 12, 13 become ''1'' and ''0''. Accordingly, a detecting circuit of an error of the transmitting system can be constituted of an NOR gate 15 which inputs the outputs of the CRCC operators 12, 13, and an additional information synchronizing signal can be detected by the output of the CRCC operating circuit 13. |
