The Problem: A high speed workstation has 64 bit words and 64 bit addresses with address resolution at the byte level. Assuming a direct mapped cache with 8192 64 byte lines, how many bits are in each of the following address fields for the cache? 1) byte 2) Index 3) Tag?
I know that an address for specifying data within a cache is 64 bits.
I know that an address for a cache has to have the byte, index, and tag field so
byte + index + tag = 64
The index field should take up 13 bits to account for the 8192 byte lines
How many bits would be in the byte field though? I know that a processor processes one word at a time and each word consists of 8 bytes. A 64 byte cache line would contain 8 words. Would this byte field need to identify each word or each byte itself. If it was byte itself, it be 6 bits but if it was word it be 3 bits.
If I had to take a stab, I would say the byte field needs to be 3 bits to identify each word because it doesn't make sense for the processor to just process one byte. Can anyone confirm my suspicisions?