Digital Logic and Microprocessors Flashcards
7 cards from real BEE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Digital Logic and Microprocessors flashcards as text
Which Boolean expression represents the output of a 2-input XNOR gate?
Answer: A·B + A'·B'
XNOR outputs 1 when both inputs are equal, expressed as A·B + A'·B'.
In a JK flip-flop, what happens when both J=1 and K=1 on the active clock edge?
Answer: Output toggles
When J=K=1, the JK flip-flop toggles its output on each active clock edge.
A 4-bit ripple carry adder adds two 4-bit numbers. What is the maximum propagation delay if each full adder has a carry propagation delay of 10 ns?
Answer: 40 ns
In a ripple carry adder, carry propagates through all 4 stages, giving 4 × 10 ns = 40 ns total delay.
What is the purpose of the program counter (PC) in a microprocessor?
Answer: Holds the address of the next instruction to fetch
The program counter holds the memory address of the next instruction to be fetched and executed.
Which addressing mode uses the content of a register as the memory address?
Answer: Register indirect
Register indirect addressing uses the value stored in a register as the effective memory address.
How many memory locations can be addressed by a microprocessor with a 16-bit address bus?
Answer: 64 KB
A 16-bit address bus can address 2^16 = 65,536 = 64 K locations.
In a Karnaugh map, which grouping size is NOT valid?
Answer: 3
K-map groups must be powers of 2 (1, 2, 4, 8, 16...); groups of 3 are invalid.