[phyrrus9]

So, I've been collecting electronics components for the last month so that I could design and physically build myself a small CPU. I finally figured out an instruction set I want, and got to work today on the ALU. The instruction set is as follows:

Code:

Registers: R0-R9 R7 is stack pointer R8 is link register R9 is program counter ALU ops (reg-reg): ADD SUB NEG INV LSH RSH AND ORR XOR MOV (also accepts constant) CMP (also accepts constant) mem: LDR STR PSH POP other (either constant or register): BRA JMP INP (register only) OUT

And, just because it looks pretty, here's a graphic of the schematic for the ALU instructions:




Let me know what you guys think. So far, the bill of materials is just under $30. When finished, this might be a fun project for those of you that want to learn this stuff (ill release my schematics if people are interested)

[Losi]

Holy shit that's cool. Quite an ambitious project i'd have to say. Keep us updated!

[Cr3aTor]

That's a nice project, I might give it a try.
Good job and thanks for sharing.

[Jimbo39238]

That is awesome dude, the schematics would indeed be cool

[phyrrus9]

That's a nice project, I might give it a try.
Good job and thanks for sharing.

I encourage you to do so. The difficulty with something like this isn't the design, it's the optimization. With a basic understanding of digital logic you can build your own without issue.

[Cr3aTor]

That's a nice project, I might give it a try.
Good job and thanks for sharing.

I encourage you to do so. The difficulty with something like this isn't the design, it's the optimization. With a basic understanding of digital logic you can build your own without issue.

I'm actually thinking of a series based on my journey into electronics and this project would most probably be part of it.

[OversouL]

I'd like to see more posts about this project. It will be an interesting read. I already forgot my computer architectures class and it will be interesting for me if you show how you designed this from the start.

[zorrophreak]

Looks pretty sexy my dude, I'll brush up on 8bit shit soon and I'll give this a shot with you!

[phyrrus9]

Looks pretty sexy my dude, I'll brush up on 8bit shit soon and I'll give this a shot with you!

I expect to see some decoder logic soon. You're looking at a completed ALU!

[phyrrus9]

An update for you guys. I decided to run a test and see how difficult it would be to do it using surface mount components and printed circuit boards. Here's the drawings from that: I drew up the ALU/XOR circuit

Schematic:


Gerber, all layers


Mock up (top side)


Mock up (bottom side)