| 摘要 |
PURPOSE:To improve the overall reliability of a system by checking the detecting history of errors by a flag bit for each word where an error is detected. CONSTITUTION:The flag bits F showing the error correcting or detecting histories are added to memory units A-C for each word. In case the data bit errors excluding the bits F are detected with the units A-C respectively or the bits F are kept turned on, the subflag signals are turned on for each word. At the same time, the bit F of the address is turned on for such a memory unit where the general output is not coincident with each output of the units A-C. Then the output of the memory unit whose subflag signal is not turned on yet is defined as the general output. Thus it is possible to check later the miscorrection of errors even in case those units A-C are once corrected wrong and then to prevent such a case where the wrong data which is unable to detect the miscorrection of a 3-bit error, for example, is delivered as a general output.
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