METHOD AND DEVICE FOR CONTROL OF DATA TRANSFER

摘要

PURPOSE:To omit a special control line by using an existing transfer request signal to instruct the invalidation of data when an error occurs. CONSTITUTION:A data transfer request signal and the data are transmitted before the deciding result is known for an error of the data to be transmitted. When the error is detected, the production of the data transfer request signal is stopped in a synchronizing cycle. A channel, a CPU, etc., of the data reception side fetch temporarily data when a transfer request signal is received and then validates the fetched data only in the case a data transfer request signal is transmitted in the following synchronizing cycle. While the data are invalidated in the case the data transfer request signal is not transmitted yet. Then a queuing state is kept until a transfer request signal is received again. Thus it is possible to correct and invalidate the transfer of data without using any special signal line.