Question

An adder with 11 gates and if a latch unit requires 4 units .. What is the maximum speed up that can be achieved by pipelining the adder

Answer 1

The OR gate gets its name from the fact that it behaves after the fashion of the logical inclusive "or." The output is "true" if either or both of the inputs are "true." If both inputs are "false," then the output is "false."



OR gate


Input 1Input 2Output    111 1111

 

The XOR ( exclusive-OR ) gate acts in the same way as the logical "either/or." The output is "true" if either, but not both, of the inputs are "true." The output is "false" if both inputs are "false" or if both inputs are "true." Another way of looking at this circuit is to observe that the output is 1 if the inputs are different, but 0 if the inputs are the same.

 



XOR gate

Input 1Input 2Output    111 111 

 

A logical inverter , sometimes called a NOT gate to differentiate it from other types of electronic inverter devices, has only one input. It reverses the logic state.

 



 

Inverter or NOT gateInputOutput1  1

 

The NAND gate operates as an AND gate followed by a NOT gate. It acts in the manner of the logical operation "and" followed by negation. The output is "false" if both inputs are "true." Otherwise, the output is "true."



NAND gate

Input 1Input 2Output  1 111 111 

 

The NOR gate is a combination OR gate followed by an inverter. Its output is "true" if both inputs are "false." Otherwise, the output is "false."



NOR gate

Input 1Input 2Output  1 1 1  11 

 

The XNOR (exclusive-NOR) gate is a combination XOR gate followed by an inverter. Its output is "true" if the inputs are the same, and"false" if the inputs are different.



XNOR gate

Input 1Input 2Output  1 1 1  111