| 摘要 |
An integrated circuit includes an adder (210) having a first adder circuit (220) for receiving a portion of the operands to be summed, along with corresponding carry-in inputs (250, 252). The first adder circuit provides a sum output (228) and carry-out outputs (254, 256). A second adder circuit (230) receives another portion of the operands to be summed, along with corresponding carry-in inputs (268, 270). Multiplexers (276, 278) between the first and second adder circuits determine whether the carry-in inputs to the second adder circuit are the same the carry-in inputs to the first adder circuit or whether the carry-in inputs to the second adder circuit are independent. <IMAGE> |
