CMSC 131 LE1

What is the result of 1 AND (0 OR(NOT(1)))?

• 0

• 1

• There is not enough information to answer the question.

Does the order of the input bits in this implementation matter?

• Yes, ordering it c, a, b (from top to bottom) would result in a different output.

• No, the order of the input bits does not impact the chip's output.

Which of these statements are true?

• The chip interface describes what the chip is doing; the chip implementation specifies how the chip is doing it.

• There is only one possible implementation for every interface.

• The user of the chip is interested in the chip interface; the builder of the chip is interested in the chip implementation.

Refer to the truth table.

Suppose the second row in the truth table (x=0, y=0, z=1) also had a value of f=1.

What would you add to the Boolean expression?

• OR (NOT(x) AND y AND z)

• AND (x AND NOT(y) AND z)

• OR (NOT(x) AND NOT(y) AND z)

• OR (x AND y AND z)

How would you implement the red chip (rightmost part of the diagram) in HDL?

• OR (a=a, b=b, out=out)

• OR (a=aAndNotb, b=notaAndb, out=out)

• OR (a=aAndNotb, b=bAndNota, out=aAndNotbOrb)

• OR (a=nota, b=notb, out=out)

Which of these statements are true?

You can use the following XOR truth table.

• The XOR gate outputs 1 if and only if its two input bits are unequal.

• The XOR gate's output differs from the AND gate's output on all possible inputs.

• The XOR gate outputs 0 if and only if the sum of the input bits is an even number.

• The XOR gate's output differs from the OR gate's output only on the input a=1, b=1.

What would be the logical equivalent of NAND(x,x)?

Remember NAND(x,x) is defined to be NOT(x AND x). Here is the truth table.

• x

• OR(x,x)

• AND(x,x)

• NOT(x)

Which of these operations is NOT implemented by the counter that you will build in project 3?

• Set to 0.

• Increase by 1.

• Decrease by 1.

• Set to a given input value.

What is the difference between a register's width and a register's address?

• They are the same.

• Address is the same for all registers, width is unique for each register.

• Width is the amount of data a single register hold, address is the location of the register within a larger chip.

• The address of a register is a logarithm of its width.

Why do we use discrete time steps instead of continuous time?

• To ensure the system state is stabilized.

• It is faster.

• It prevents delays in electric signals, moving electrons instantaneously from one place to another.

• Because time is discrete, due to limits of quantum time.

• All of the above.