Question

Consider a logical address space of eight pages of 1024 words each, mapped into a physical memory of 32 frames. How many bits are there in the logical address and in the physical address, respectively?

• A. 10, 5
• B. 15, 13
• C. 13, 15
• D. 15, 10

Hint:

Break the address calculation into 'number of pages/frames' and 'words per page/frame' to find the total bits.

Answer 1

The Correct Option is B

To calculate the number of bits in the logical and physical addresses: Logical address: Number of pages = 8, so Number of bits for page number = log2(8) = 3. Each page contains 1024 words, so Number of bits for word within a page = log2(1024) = 10. Total bits in the logical address = 3 + 10 = 13. Physical address: Number of frames = 32, so Number of bits for frame number = log2(32) = 5. Each frame contains 1024 words, so Number of bits for word within a frame = 10. Total bits in the physical address = 5 + 10 = 15.