JPS5476117A - Diagnosis system of error correction circuit - Google Patents

Abstract

PURPOSE: To facilitate diagnosis of an error track pointer by setting all the error correction track signals formed from syndromes at a constant value and forcefully applying the correction instruction signal of an error over two tracks.

CONSTITUTION: When a pointer diagnosis signal I is applied, the outputs of a syndrome comparator 3, i.e., error correction track signals B, all become the signal of a preset value, e.g., all "1". At the same time, an inversion signal is applied to AND 4 via NOT 16 and therefore the AND 4 is held de-energized during this time. Further the signal I is applied to AND 5 via OR 14 and two track errors occur and it becomes as if the error correction signal H has been applied to the AND 5. Hence, in this case, all the error correction track signals B become a specified value, all "1" signal, etc. and therefore, the error correction signal D' becomes based only on the output signal F of an error track pointer 11 and if the data E having been error- corrected by the signal D' is examined, the diagnosis of the pointer 11 may be performed.

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