D-6 Flashcards
How to “DeMorganize”
Change the operator
Negate all the gate’s inputs and outputs
Boolean algebra assumes that variables are either
on or off
All flip-flops have ___________________ outputs
complementary
For a R-S flip-flop the R and S stand for
Reset and set
For R-S flip-flop what happens when S and R equal 1?
Both Q and bar Q would go low. This is called and illegal, or prohibited condition
For NAND gate R-S FF what is the prohibited input?
R and S = 0
making Q and bar Q = high
Describe an asynchronous flip-flop
this means the outputs will respond to the R and S input data when that data changes
Three types of synchronous flip-flops are
Clocked R-S FF
D type FF
J-K FF
Describe a synchronous FF
The data inputs determine what the outputs will be, but the clock inputs determine when the outputs will change.
D type FF is a
leading-edge triggered FF
J-K FF is the most widely used. Why?
possesses a unique toggle feature
can be adapted to any of the other three FF
Many J-K FF use __________________ triggering
trailing-edge
In input state will a J-K FF toggle?
When J and K = 1
What is the formal term for flip-flop
Bistable multivibrator
List the four common FF
R-S Latch FF
D (data) FF
J-K FF
Clocked R-S
What devices form the building blocks for counters and shift registers?
J-K or D type FF
What is meant by the modulus of a counter?
the number of different states a counter goes through before reset.
A multiplexer is the electronic equivalent of what kind of mechanical switch?
Rotary selector switch
List 5 advantages ICs have over discrete ccts
- High reliability
- Small size
- Low cost
- High speed
- Less power consumed
What are the disadvantages of ICs?
- Current and voltage must be low
- Limited component selection
- Non-repairable
A common way to classify an IC is either
- Digital (sometimes called logic)
- Linear (sometimes called analogue)
List the four levels of integration for IC
- Small-scale integration (SSI) Fewer than 12 gates
- Medium-scale integration (MSI) 12 to 99 gates
- Large-scale integration (LSI) 100 to 999 gates
- Very large-scale integration (VLSI) 10 000 or more gates
What type of transistors are used in transistor transitor logic (TTL)
bipolar transistors
The CMOS logic family uses
field-effect transistor (FETS)
A CMOS logic chip is susceptible to being wrecked by
static electricity
What does DIP stand for?
Dual-in-package
In a TTL chip a floating input behaves as a
high
In a CMOS chip a floating input can cause
- unpredictable output
- may create excessive heating
How to handle floating inputs for AND and NAND gates
may be connected directly to the supply voltage or to one of the used inputs
In a DIP, where is the highest pin number located relative to pin #1
directly opposite
Which two of the logic families have the faster switching speed
TTL
