| 摘要 |
A programmable function block 20 comprises a logic block 21 including a full adder 31 and at least one preposition logic 32, and an input block 22 including programmable input switch units 40-1 through 40-9 for use in selectively switching a HIGH logic level signal, a LOW logic level signal, and a signal on interconnection lines 50. The preposition logic 32 comprises an exclusive OR circuit 32-1 and a multiplexer 32-2 and functions as various different logic circuits by means of setting some of the inputs thereof to a HIGH logic level or a LOW logic level. Thus, the logic block functions as various different logic circuits depending on the state of the inputs. In addition, the full adder provides fast arithmetic operation.
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