📝 Direct memory access in I/O Hardware

Q1. A computer needs to copy a 4 MB file from a disk controller to main memory. Which benefit does using DMA provide over having the CPU copy each byte?

💡 Difficulty: easy | ✅ Correct: A

Q2. An embedded system reads sensor data at 1 kHz and stores it in a buffer. Which condition makes DMA the preferred method instead of programmed I/O?

💡 Difficulty: medium | ✅ Correct: D

Q3. Designing a DMA engine for a PCI Express device that must address up to 2 TiB of RAM, which bus width is required to transfer a full 64‑bit address in a single transaction?

💡 Difficulty: hard | ✅ Correct: B