| 摘要 |
PURPOSE:To efficiently detect abnormality in an address signal by writing data by an address signal obtained by inverting an optional bit to form data different from data written in the memory prior to the inversion. CONSTITUTION:A processor 5 forms an address signal to be successively increased from the head address of the memory 2, sends it to the memory 2 through an address bus and sends it to the data bus and writes data to/in the memory 2. At that time, data surely different from the data written in the memory 2 are sent by using an address signal obtained by inverting an optional bit out of plural bits in the former address signal. The data written in the memory 2 by the address signal having the one-bit error are different from the data written in the corresponding area by the address signal having no error bit, and when the different data are read out by the address signal having the one-bit error, the error is detected without fail. Consequently, the memory 2 is efficiently diagnosed. |
