Question

What leads to the development of MESI and MEI protocol?

(a) cache size

(b) cache coherency

(c) bus snooping

(d) number of caches

This question was posed to me during an online interview.

Asked question is from Writing Scheme of Cache Memory topic in chapter Memory Systems of Embedded Systems

Answer 1

Correct choice is (b) cache coherency

For explanation I would say: The problem of cache coherency lead to the formation of two standard mechanisms called MESI and MEI protocol. MC88100 have MESI protocol and MC68040 uses an MEI protocol.