摘要 |
In an adder circuit, a block carry generation logic over three consecutive digits is produced from the following equations.In other words, the block carry generation logic /G0 is produced by a single PMOS transistor, a series circuit formed of two PMOS transistors connected in series, and a series circuit formed of three PMOS transistors connected in series. The block carry generation logic G0 is produced by a single NMOS transistor, a series circuit formed of two NMOS transistors connected in series, and a series circuit formed of three NMOS transistors connected in series. Block carry generation logics can be formed in such a way as to achieve not only a reduction of the layout area but also a higher operation rate.
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