Project 5 Computer Architecture

Project 5
Computer Architecture

Grading:
(A) Project Demo [60%]: TBA
You will be graded for correctness of the chips (hdl) you have designed and coded. We will be
running offline test of all your HDL codes using Nand2tetris software (Hardware Simulator). The
same simulator you will be using to check your chips in the course of this project. So, make sure to
test and verify your codes before finally submitting on eCampus.
(B) Lab Quiz [40%]: TBA
Rubric: The rubric allocation for chips is shown at the end of this document. Each chip needs to pass all its
test cases to get the points, else you will receive 0 on that chip.
Deliverables & Submission: Turn in a zip file in the format FirstName-LastName-UIN.zip containing the 3
HDL files(Memory.hdl, CPU.hdl and Computer.hdl). Put your full name in the introductory comments
present in each HDL file. Use relevant code comments and indentation in your code. Submit this zip file on
eCampus.
Late Submission Policy: Refer to the Syllabus
Background
In previous projects we've built the computer's basic processing and storage devices
(ALU and RAM, respectively). In this project we will put everything together, yielding the
complete Hack Hardware Platform. The result will be a general-purpose computer that can run
any program that you fancy.
Objective
Complete the construction of the Hack CPU and computer platform, leading up to the top-most
Computer chip.
Chips
Chip (HDL) Description Testing
Memory.hdl Entire RAM
address space Test this chip using Memory.tst and Memory.cmp
CPU.hdl The Hack CPU
Recommended test files: CPU.tst and CPU.cmp.
Alternative test files (less thorough but do not require
using the built-in
DRegister): CPU-external.tst and CPU-external.cmp.
Computer.hdl The platform's
top-most chip
Test by running some Hack programs on the constructed
chip. See more instructions below.
Contract
The computer platform that you build should be capable of executing programs written in
the Hack machine language, specified in Chapter 4. Demonstrate this capability by having your
Computer chip run the three test programs given below.
Testing
Testing the Memory and CPU chips: It's important to unit-test these chips before proceeding to
build the overall Computer chip. Use the the test scripts and compare files listed above.
Testing the Computer chip: A natural way to test the overall Computer chip implementation is
to have it execute some sample programs written in the Hack machine language. In order to
perform such a test, one can write a test script that (i) loads the Computer.hdl chip description
into the supplied Hardware Simulator, (ii) loads a machine-level program from an external .hack
file into the ROM chip-part of the loaded Computer.hdl chip, and then (iii) runs the clock enough
cycles to execute the loaded instructions. We supply all the files necessary to run three such tests,
as follows:
Program Comments
Add.hack
Adds up the two constants 2 and 3 and writes the result in RAM[0].
Recommended test:ComputerAdd.tst and ComputerAdd.cmp. Alternative test
(less thorough but only requires usage of the built-in
RAM16K): ComputerAdd-external.tst and ComputerAdd-external.cmp.
Max.hack
Computes the maximum of RAM[0] and RAM[1] and writes the result in
RAM[2]. Recommended test:ComputerMax.tst and ComputerMax.cmp.
Alternative test (less thorough but only requires usage of the built-in
RAM16K): ComputerMax-external.tst and ComputerMax-external.cmp.
Rect.hack
Draws a rectangle of width 16 pixels and length RAM[0] at the top left of the
screen. Recommended test ComputerRect.tst and ComputerRect.cmp. Alternative
test (less thorough but does not require usage of any built-in
chips): ComputerRect-external.tst and ComputerRect-external.cmp.
Before testing your Computer chip on any one of the above programs, read the relevant .tst file
and be sure to understand the instructions given to the simulator. Appendix B of the book may be
a useful reference here.
Resources
The relevant reading for this project are Chapter 5, Appendix A, and Appendix B (as a reference,
and use TAMU mail id to access). Specifically, all the chips described in Chapter 5 should be
implemented in the Hardware Description Language (HDL) specified in Appendix A.
The resources that you need for this project are the supplied Hardware Simulator and the files
listed above.
Implementation Tips
Complete the computer's construction in the following order:
Memory: This chip includes three chip-parts: RAM16K, Screen, and Keyboard. The Screen and
the Keyboard are available as built-in chips, and thus there is no need to implement them.
Although the RAM16K chip was built in Project 3, we recommend using its built-in version, as it
provides a debugging-friendly GUI.
CPU: This chip can be constructed according to the proposed CPU implementation given in
Figure 5.9 of Chapter 5, using the ALU and register chips built in Projects 2 and 3, respectively.
We recommend though using built-in chip-parts instead, in particular A Register and D
Register. The built-in versions of these two chips have exactly the same interface and
functionality as those of the Register chip specified in Chapter 3; however, they feature GUI
side-effects that come handy for testing purposes.
In principle, your CPU implementation may include internal chips of your own specification, i.e.
chips not mentioned in Figure 5.9 of Chapter 5. However, this is not recommended, and will
most likely yield a less efficient CPU design. If you choose to create new chips not mentioned in
the book, be sure to document and unit-test them carefully before you plug them into the
architecture.
Instruction memory: Use the built-in ROM32K chip.
Computer: The top-most Computer chip can be constructed according to the proposed
implementation shown in Figure 5.10 of Chapter 5.
Tools
All the chips mentioned in this project, including the topmost Computer chip, can be
implemented and tested using the supplied Hardware Simulator. Here is a screenshot of testing
the Rect.hack program on a Computer chip implementation.
The Rect program illustrated above draws a rectangle of width 16 pixels and length RAM[0] at
the top-left of the screen. Now here is an interesting observation: normally, when you run a
program on some computer, and you don't get the desired result, you conclude that the program
is buggy. In our case though, the supplied Rect program is bug-free. Thus, if running this
program yields unexpected results, it means that the computer platform on which it runs
(Computer.hdl and/or some of its lower-level chip parts) is buggy. If that is the case, you have to
debug your chips.
Rubric(60 Points):
Your turned in files will be graded based on the following tests:
CPU.tst: 15
Memory.tst: 10
CPU-external: 5
ComputerAdd: 5
ComputerAdd-external: 5
ComputerMax: 5
ComputerMax-external: 5
ComputerRect: 5
CmputerRect-external: 5
Make sure you did the tests on each of them