neo-vincent/cpu-cache-simulator

A CPU cache simulator written in Python

CPU Cache Simulator

This is a simulator for a CPU cache that I wrote for a college course. It's meant to demonstrate some of the different replacement, write, and mapping policies that CPUs can implement.

To run the CPU cache simulator:

simulator.py [-h] MEMORY CACHE BLOCK MAPPING REPLACE WRITE

Once you start the simulator, you can enter commands to modify and read from the memory (which is randomized on initilization), and therefore indirectly modify the cache. You can also print the contents of the memory and cache, as well as view statistics about the cache's performance.

The arguments and commands, along with their descriptions, are listed below.

Arguments

MEMORY - size of main memory in 2^N bytes

CACHE - size of the cache in 2^N bytes

BLOCK - size of a block of memory in 2^N bytes

MAPPING - mapping policy for cache in 2^N ways

• 0 - direct mapping
• >0 - 2^N way associative

REPLACE - replacement policy for cache

• LRU - least recently used
• LFU - least frequently used
• FIFO - first-in, first-out
• RAND - random

WRITE - write policy for cache

• WB - write back
• WT - write through

Commands

read ADDRESS - read byte from memory

write ADDRESS BYTE - write random byte to memory

randread AMOUNT - read byte from random location in memory AMOUNT times

randwrite AMOUNT - write random byte to random location in memory AMOUNT times

printcache START LENGTH - print LENGTH lines of cache from START

printmem START LENGTH - print LENGTH blocks of memory from START

stats - print out hits, misses, and hit/miss ratio

quit - quit the simulator

Example

Here is an example run:

python simulator.py 10 7 3 2 LRU WT

This creates a simulation with 2^10 bytes of memory, 2^7 bytes of cache, uses 8-way (2^3) associate mapping, least-recently used replacement policy, and write-through write policy.