Study Guide #2 Flashcards
What is a combinational circuit?
circuit with more than one output
MUX operations
select lines determine which input goes to output. Select lines represent binary form of output #.
DEMUX operations
select lines determine which output the input goes to. Select lines represent binary form of output #.
MUX uses
- implement boolean functions
- implement truth table
Encoder operations
receives one high input and outputs the binary form through the access lines.
Decoder operations
receives binary input of number through access lines and outputs to corresponding output line.
Which Encoder/Decoder has an enable line?
Decoder
Which of the four chips (MUX, DEMUX, Encoder, and Decoder) are the same just a different view?
DEMUX and Decoder
How to implement boolean function using MUX
Draw MUX according to number of variables (ex. A,B,C = 3 seclect lines), then tie each input line from function to power and ground
How is a decoder used to implement a boolean function?
same way as MUX
Explain the SR latch
sets and resets circuit
What is the problem with the SR latch?
invalid when both inputs are high
Explain the clocked SR latch
timed set and reset
What is the problem with the clocked SR latch?
When clock is high, it can change status multiple times
JK flip-flip operation
set and reset with added protection
SR flip-flop operation
set and reset
D flip-flip operation
hold data
T fliop-flop operation
stay same or inverse
SR flip-flip characteristic table
0 0 Q(T)
0 1 0
1 0 1
1 1 NOT ALLOWED
JK flip-flop characteristic table
0 0 Q(T)
0 1 0
1 0 1
1 1 Q’(T)
D flip-flip characterictic table
0 0
1 1
T flip-flop characteristic table
0 Q(T)
1 Q’(T)
JK flip-flop excitation table
J K Q(T) Q(T+1)
0 0 0 X
0 1 1 X
1 0 X 1
1 1 X 0
How to convert JK flip-flop into D flip-flop
Pass D into J, then use inverter to pass D’ into K
