Digital data transmission system having error detecting and correcting function

摘要

An error correction code of the product sign format is added to the input information data to form coded data. The coded data are then NRZI converted and recorded onto a record medium together with identification data of a predetermined data pattern. Error detecting and correcting processing is executed with reproduction data obtained from the record medium to reproduce the data recorded on the record medium. The device comprises an NRZI converting circuit for outputting the information data as they are without NRZI converting the same but for NRZI converting the coded data using the last bit of the identification data as an initial value, and a memory controlling circuit (501) for controlling writing and reading of a memory, which is provided to convert the reproduction data from a series of inner codes into another series of outer codes, so that write address information for the memory which is obtained from the reproduction data may be compensated for when it is not obtained properly and outer code error detecting and correcting processing may be executed in a trouble-free way.