Block Transfer - Intro to Computer Architecture - Homework, Exercises of Computer Architecture and Organization

Download Block Transfer - Intro to Computer Architecture - Homework and more Exercises Computer Architecture and Organization in PDF only on Docsity! Computer Architecture Homework #7 1. Suppose we had a block transfer from an I/O device to memory. The block consists of 2048 words and one word can be transferred to/from memory at a time. For each of the following, indicate the number of interrupts needed to transfer a block using: a) DMA (direct-memory access) b) interrupt-driven I/O c) programmed-I/O 2. Give an example where programmed-I/O might be used. 3. Explain the difference between programmed I/O and interrupt-driven I/O. 4. Explain the difference between interrupt-driven I/O and DMA. 5. Assume special I/O instructions are used to fill I/O-controller registers. Why can’t a user program use these instructions to communicate with the I/O device directly and “by-pass” the operating system’s protection checking? 6. Assume that memory-mapped I/O is used. Since Load and Store instructions are used to communicate with the I/O-controller registers, why can’t a user program communicate with the I/O device directly and “by-pass” the operating system’s protection checking? 7. Suppose that you are setting up a computer system as a database server for your company. You have enough money to buy a 4 disk RAID array which can configured as either:
RAID 0 (nonredundant),
RAID 1 (mirrored)
RAID 3 (bit-interleaved with a parity disk)
RAID 5 (block-level with distributed parity blocks) How would you configure the RAID array? (Justify you answer) Docsity.com