CET Digital Logic & Microprocessors 3 — Questions and Answers
Question 1: A euthanasia system microcontroller must read a temperature sensor every 500 milliseconds. Which microprocessor feature is best suited to trigger this periodic reading without continuously consuming CPU cycles?
- Direct Memory Access (DMA)
- Hardware timer/interrupt (Correct answer)
- Stack pointer
- Accumulator register
Correct answer: Hardware timer/interrupt
Hardware timers generate periodic interrupts that signal the CPU at precise intervals, freeing the processor from constant polling loops.
Question 2: In Boolean algebra used for designing euthanasia equipment safety logic, which law states that A + (B × C) = (A + B) × (A + C)?
- De Morgan's Law
- Distributive Law (Correct answer)
- Commutative Law
- Associative Law
Correct answer: Distributive Law
The Distributive Law in Boolean algebra allows OR to distribute over AND and vice versa, useful for simplifying complex safety logic circuits.
Question 3: A CO2 euthanasia controller uses a 4-bit DAC (Digital-to-Analog Converter) to control gas flow rate. How many distinct flow rate levels can this DAC produce?
- 4
- 8
- 16 (Correct answer)
- 32
Correct answer: 16
A 4-bit DAC produces 2^4 = 16 distinct analog output levels, from 0 to full scale.
Question 4: Which microprocessor bus carries data between the CPU, memory, and peripherals in a euthanasia equipment controller?
- Address bus
- Control bus
- Data bus (Correct answer)
- Power bus
Correct answer: Data bus
The data bus is a bidirectional pathway that transfers actual data values between the CPU, memory, and I/O peripherals.
Question 5: De Morgan's first theorem states that NOT(A AND B) equals what expression?
- NOT(A) AND NOT(B)
- NOT(A) OR NOT(B) (Correct answer)
- A OR B
- NOT(A AND NOT(B))
Correct answer: NOT(A) OR NOT(B)
De Morgan's first theorem: the complement of a product (NAND) equals the sum of the complements — NOT(A AND B) = NOT(A) OR NOT(B).
Question 6: A euthanasia system uses a flip-flop to remember whether a safety alarm has been triggered. Which flip-flop type has only SET and RESET inputs and is most commonly used for simple alarm latching?
- D flip-flop
- JK flip-flop
- T flip-flop
- SR (Set-Reset) flip-flop (Correct answer)
Correct answer: SR (Set-Reset) flip-flop
The SR flip-flop is the most basic bistable element with dedicated Set and Reset inputs, making it ideal for alarm latching applications.
Question 7: In an embedded microcontroller used for euthanasia equipment, GPIO stands for what?
- General Purpose Input/Output (Correct answer)
- Guided Program Interrupt Operation
- Global Processor I/O
- Graphical Processing Interface Output
Correct answer: General Purpose Input/Output
GPIO (General Purpose Input/Output) pins on a microcontroller can be individually configured as digital inputs or outputs to interface with sensors, valves, and indicators.
CET Digital Logic & Microprocessors 3
A euthanasia system microcontroller must read a temperature sensor every 500 milliseconds.
Which microprocessor feature is best suited to trigger this periodic reading without continuously consuming CPU cycles?