| 摘要 |
PURPOSE:To obtain a necessary non-defective function module by counting the prescribed number of non-defective function modules by a counter circuit, and thereafter, detaching the remaining function modules. CONSTITUTION:A switching circuit 8 selects an output data line of a storage module 1, when the state of an output data line 7 of a flip-flop 4 is ''1'', and outputs data of the storage module 1 to an output data line 9. On the other hand, in case when the storage module 1 is a defective, the output data line 3 of the storage module 1 remains initial and it is fixed to ''0'' or ''1''. In this case, no clock is supplied to a clock terminal CLK of the flip-flop 4 from the output data line 3, and the state of the flip-flop 4 remains ''0'' which has been set in the beginning. Accordingly, the switching circuit 8 selects an input data line 2 of the storage module 1, and detaches a defective storage module 1. That is to say, discrimination is made as to whether the function module is non-defective or defective by a small quantity of hardware of the switching circuit, and the quantity of hardware is made less. |
