2Q cache

Overview

I implemented 2Q cache strategy from paper "2Q: A Low Overhead High Performance Buffer Management Replacement Algorithm" written by Theodore Johnson and Dennis Shasha. It is written in VHDL and supports my FORTH-processor, which runs on a Spartan 3A DSP board from Xilinx. I think it can be adapted for other processors easily.

parameters, user defineable:
- blocksizeld ld of size of tagram
- ldways ld of number of tagrams (n-way associative)
- ldcachedwords ld of number of 32-bit words in one cacheline

defineable too:
- ldram ld of depth of cacheram
- ldqueuelength ld of depth of fifo (2Q strategy)

YOU have to redefine subtype RAMrange in global.vhd:
As example, Your RAM is 128 MB then
subtype RAMrange is natural range 26 downto 0;