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📝 Control Logic of 8257

📖 From An Introduction To Microprocessor 8085 • 12. Direct Memory Access Controller: 8257 • 18 questions available

Practice MCQs for Control Logic of 8257. Test your knowledge with carefully crafted questions across easy, medium, and hard difficulty levels.

🔄 Last updated: 2026-07-30

3
Easy Questions
9
Medium Questions
6
Hard Questions

📝 Sample Questions

Q1. What is the primary function of the Intel 8257 DMA controller?

🔹 A. Generate interrupts
🔹 B. Control the system clock
🔹 C. Transfer data between memory and I/O without CPU intervention
🔹 D. Decode instruction opcodes

💡 Difficulty: easy | ✅ Correct: A

Q2. Why does using DMA improve data transfer speed compared to CPU‑mediated transfers?

🔹 A. DMA allows the CPU to execute instructions faster
🔹 B. DMA eliminates the need for address decoding
🔹 C. DMA transfers data directly over the bus, freeing the CPU to perform other tasks
🔹 D. DMA uses a higher clock frequency than the CPU

💡 Difficulty: medium | ✅ Correct: A

Q3. In what way does the 8257 enable multiple I/O devices to operate without bus conflicts?

🔹 A. It provides separate physical buses for each device
🔹 B. It assigns unique priority levels to each channel and arbitrates requests
🔹 C. It disables all devices except the one currently using the CPU
🔹 D. It uses time‑division multiplexing to share the bus among devices

💡 Difficulty: hard | ✅ Correct: A

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🔗 Related Topics

📝 Block Diagram of 8257📝 DMA Channels of 8257📝 Data Bus Buffer of 8257📝 Read/ Write Logic of 8257📝 Mode Set Register of 8257
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