[libre-riscv-dev] Introduction and Questions

Luke Kenneth Casson Leighton lkcl at lkcl.net
Fri May 15 22:55:43 BST 2020


On Fri, May 15, 2020 at 10:20 PM Jacob Lifshay <programmerjake at gmail.com> wrote:

> We will definitely need more stages in the fetch pipeline for branch
> prediction, TLB, and cache handling, I'm guessing 2 or 3 fetch stages.

oh, yes.  good catch.  ah... ok TLB is deliberately kept to very small
sizes (8 entries max)
so that it can respond in 1 cycle (or, same-cycle).  branch prediction and
cache misses, i left out because they're "extra" (but only on misses).

however for higher speeds, TLBs are often cascaded and again end up with
extra misses.  that's according to the wikipedia page on TLB :)

l.



More information about the libre-riscv-dev mailing list