BEE Digital Logic and Microprocessors 5

Question 1

What is the Boolean simplification of the expression AB + AB'?

Accepted Answer

A

Answer

AB + AB' = A(B + B') = A·1 = A by the complement and identity laws.

Question 2

A shift register can be used to perform which arithmetic operation on a binary number?

Accepted Answer

Multiplication or division by powers of 2

Answer

Shifting left multiplies by 2 and shifting right divides by 2, so shift registers perform multiplication/division by powers of 2.

Question 3

In DMA (Direct Memory Access) data transfer, what role does the CPU play during the transfer?

Accepted Answer

The CPU is bypassed; the DMA controller handles the transfer

Answer

DMA allows the DMA controller to transfer data directly between memory and I/O without CPU intervention, freeing the CPU for other tasks.

Question 4

Which of the following best describes a tri-state buffer?

Accepted Answer

A device with outputs of logic 0, logic 1, or high-impedance

Answer

A tri-state buffer can output logic 0, logic 1, or a high-impedance (Hi-Z) state that effectively disconnects the output from the bus.

Question 5

In a microprocessor's instruction cycle, which operation follows the fetch phase?

Accepted Answer

Decode

Answer

After fetching the instruction from memory, the processor decodes it to determine the operation and operands.

BEE - Bachelor of Electrical Engineering Practice Test