Description

Computer Architecture

Grading:
(A) Project Demo [60%]
You will be graded for correctness of the chips (hdl) you have designed and coded. See Rubric below.
(B) Project Quiz [40%]: TBA

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) + Cover letter
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

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

Before you start implementing these programs, make sure you are using the ORIGINAL Compilers.jar and Hack.jar files in ../nand2tetris/tools/bin/lib (recall, you might have replaced them if you did P4 Bonus question with > and < operators)
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.

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.

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.