CACHE INDexing1.1

Question

Consider a 32 bit microprocessor that has an on chip 16 Kbyte four way set associative cache. Assume that cache has a size of four 32 bit words. The set number in the cache to which the word from memory location FFFAE8FA is mapped is _________.

Answer 1

Number of cache sets = 16K / (4 * 4 * 32 / 8) = 256. 

Consecutive memory blocks will be mapped to consecutive cache sets (from left end, after offset bits we have index bits). Here we have word addressing as question asks for "word at location". So, number of offset bits = 2. So, next 8 bits are index bits. i.e., 8FA (top part of address won't affect the set) = 1000 1111 10 | 10 

which will be 62.