SR Flip Flop:

The SR Flip Flop is a simple latch that takes in two inputs, and holds (latches) the input (S) on the output line (Q). The complement of Q, aka Q', is also latched. The inputs of S=0 and R=0 does not have an affect on the current state. The undefined state can be eliminated by changing the SR Flip Flop to a D Flip Flop

A SR Flip Flop can be constructed out of two nor gates with thier outputs coupled with the opposite gates input.
			
SR Gate State Table using 2-input Nor Gates :
S	R	Q	Q'	State
-----------------------------------------
1	0	1	0	Set State
0	0	1	0

0	1	0	1	Reset State
0	0	0	1

1	1	0	0	Undefined State


SR Gate Diagram using two 2-input Nor Gates :
	________
R-------|	|
 	|  Nor  |-----X------------------Q
	|   	|     |
     ---|_______|     |
     |                |
     |                |
     |________________C_________
     		      |         |
                      |         |
     -----------------          |
     |	________               	|
     |--|	|              	|
	|  Nor  |---------------X-------Q'
	|   	|
S-------|_______|

Diagram Notes:
  Inputs: S, R	    
  Outputs: Q, Q'
  Other:
  C= The "C" in the diagram means the travelling
     connection hops over the wire it would otherwise
     cross into     
  X= The "X" is where one wire attaches to another wire


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