| 摘要 |
PURPOSE:To change optionally the number of bits of input output data by using freely a part or all parts of the memory element for the usual action system and for the replacing system through writing and reading multiplexers. CONSTITUTION:The contents of a replacing bit register 2, in which a bit position of a replaced memory element out of a usual action system memory element group 3 and corresponding to this, a bit position of a usual action -cum- replacing memory element group 4 are designated, are decoded by a decoder 5, and a selecting signal is supplied to a write multiplexer 1 and a word multiplexer 6. Then, the multiplexer 1 selects the write data corresponding to a bit position of the element when an element group 4 is used as a usual action system, and the write data corresponding to the bit position of a replacing element when the group is used as a replacing action system, and outputs to the bit position corresponding to the element group. The reading through the multiplexer 6 is also executed in the same way, and the number of bits of input output data can be optionally changed.
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