Interface basics: ADC0804 is an 8-bit analog-to-digital converter that provides parallel digital output suitable for direct connection to a microcontroller bus. Evaluate this statement.

Difficulty: Easy

Correct Answer: Correct

Explanation:


Introduction / Context:
The ADC0804 is a classic, widely taught 8-bit ADC often used in microcontroller labs. It features a parallel data output and simple control signals (Start, End-of-Conversion) that make it straightforward to hook up to an 8051-type microcontroller. This question tests basic familiarity with its resolution and interfacing style.



Given Data / Assumptions:

  • ADC0804 provides 8-bit resolution, mapping an analog input range into 256 discrete codes.
  • Parallel data lines (D0–D7) present the conversion result.
  • Control signals allow the host MCU to initiate and read conversions.
  • Proper reference and clocking (internal RC or external) are provided.


Concept / Approach:
To integrate ADC0804 with an 8051, connect D0–D7 to an 8-bit port, wire Start of Conversion and End-of-Conversion pins to GPIO or interrupt-capable lines, and ensure the reference and analog ground are appropriate. The MCU initiates a conversion, waits for EOC, then reads the 8-bit result as a single byte. Timing diagrams in datasheets guide precise sequencing.



Step-by-Step Solution:

Provide Vref/2 if scaling is desired; otherwise use default full-scale.Start a conversion by toggling the control input per the spec.Poll or interrupt on EOC to detect completion.Read D0–D7 into an 8-bit register for further processing.


Verification / Alternative check:
Measure a known DC input and confirm the digital code matches the expected fraction of full scale. Repeating across several points confirms linearity and correct interfacing.



Why Other Options Are Wrong:

Incorrect: Contradicts the established operation of ADC0804.Needs a latch / built-in DAC: Optional conveniences; not mandatory for basic MCU interfacing.


Common Pitfalls:
Forgetting to respect settling/hold times, noisy references, or floating analog grounds—all of which degrade accuracy.


Final Answer:
Correct

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion