Marie Code

© Paul Koester, Dallas County Community College, 2018

COSC 2425 – Computer Organization

Lab #7 – Set Associative Cache

Programs for embedded devices are often written in assembly language. Some embedded processors

have limited instructions, like MARIE. Create a MARIE program which determines whether a given

address is a cache hit or not. For this assignment, the cache is 2-way set associative, addresses are 8

bits, blocks are 8 bytes, and the cache has 8 blocks.

Requirements

1. The program must be written in MARIE.

2. The input is a hex address (2 hex digits), the output is 1 for a cache hit and 0 for a cache miss.

3. The cache table is

Set 0 1 5

Set 1 2 4 Set 2 3 2

Set 3 6 0

Tags

4. Unlike a real memory system, for this assignment, the cache table won’t change on a cache

miss.

Hints:

1. You have already written a multiply subroutine for MARIE. You could use a similar integer

divide subroutine for this. It could return both a quotient and a remainder.

2. I recommend writing this in Java or C++ first to test your algorithm. Write the divide method

using repeated subtraction as you will in MARIE.

3. The textbook describes the LoadI instruction, but the MARIE simulator does not recognize that.

You can accomplish the same thing using Clear and AddI.

Upload: Your MARIE source file (.mas)

Sample Output

Input: B5, Output: 0

Input: A5, Output: 1

Input: 6C, Output: 0

Input: 7D, Output: 0

Input: 8B, Output: 1