Digital Logic and Microcomputers Flashcards
7 cards from real GROL 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 Microcomputers flashcards as text
What does an analog-to-digital converter (ADC) do in a digital communications system?
Answer: Converts a continuous analog signal into discrete digital binary values
An ADC samples and quantizes a continuous analog signal, converting it into a series of discrete binary numbers.
What is the Nyquist sampling theorem's requirement for accurately digitizing an analog signal without aliasing?
Answer: Sample at least twice the highest frequency present in the signal
The Nyquist theorem requires a sampling rate of at least twice the highest frequency component to prevent aliasing errors.
In microprocessor terminology, what is an interrupt?
Answer: A signal that causes the CPU to suspend its current task and execute a special service routine
An interrupt is an asynchronous signal from hardware or software that causes the CPU to pause, save its state, and execute an interrupt service routine (ISR).
What is the resolution of an 8-bit digital-to-analog converter (DAC) expressed as a percentage of full scale?
Answer: 0.39%
An 8-bit DAC has 2⁸ = 256 steps, so resolution = 1/256 ≈ 0.39% of full-scale output.
In a microprocessor system, what is the difference between memory-mapped I/O and isolated I/O?
Answer: Memory-mapped I/O assigns peripherals addresses in the memory space; isolated I/O uses a separate address space with dedicated I/O instructions
Memory-mapped I/O treats peripherals as memory locations; isolated (port-mapped) I/O uses a separate address space accessed via IN/OUT instructions.
What is the purpose of a watchdog timer in a microcontroller-based system?
Answer: Automatically resets the processor if software fails to periodically reset the timer
A watchdog timer resets the microcontroller if the software freezes or crashes and fails to periodically 'kick' (reset) the timer before it overflows.
In digital communications, what is the function of a parity bit?
Answer: Provides a basic error detection mechanism by making the total number of 1s even or odd
A parity bit is appended to a data word to make the total number of 1-bits either even (even parity) or odd (odd parity), enabling single-bit error detection.