Cache memory. What? Small, but fast (SRAM) memory closest to the CPU registers in the memory hierarchy. Can be on the CPU (level 1 cache), or on the motherboard (level 2 cache, usually connected via a dedicated fast bus).
Single word transfer
Block transferCaches, more on How?
RA is the Requested Address by the CPU
* Policy required, unless Direct Mapped
block in cacheMMU’s basic memory request cycle