METHOD AND DEVICE FOR DETECTING ERROR OF COUNTING CIRCUIT AND COUNTING DEVICE AND ADDRESS SIGNAL GENERATING DEVICE

摘要

PURPOSE:To prevent an erroneous processing caused by a malfunction of a counting circuit by adding or subtracting a value corresponding to a difference to a discrete value whose error is to be detected, to or from a discrete value, comparing a result of operation and the discrete value and detecting a counting error. CONSTITUTION:A counting circuit 8 executes counting, whenever a clock signal 16 is inputted, and an output signal 19 increases by '1' each successively such as (n-1), (n),.... An adding circuit 9 adds [1] to the output signal 19, and output signal 20 of for instance, [(n-1)+1] is outputted, inputted to a holding circuit 10 by a timing of a clock signal 17 of the same phase as that of the clock signal 16, and simultaneously, the clock signal 16 is inputted to the counting circuit 8, as well, and the output signal 19 of a result of counting of a value [n] is outputted. Subsequently, an output signal 21 of the holding circuit 10 and the output signal 19 of the counting circuit 8 are compared by a comparing circuit 11, and when the output signal 19 is [n] at the time when the output signal 21 is [(n-1)+1], as for the counting circuit 8, it is known that said signal becomes a value of (n-1), and thereafter, the next clock signal is counted correctly, and a high level signal 22 for showing the coincidence is outputted.