I'm in my first real design class and I have to create a simple processor in VHDL and implement it on a FGPA board later on. I'm designing the ALU right now and I would like to know what's the purpose of having a multiplexer implemented with the adder-*** -subtractor? If you know of a website that offers schematics so that I can actually see where they are that'd be great as well (googling hasn't been rewarding as of yet) .Maybe if I knew what a multiplexer does to help a ACS I'd actually be able to design it..thanks guys!
2006-10-08 13:20:51 · 1 answers · asked by Galbadian 2 in Science & Mathematics ➔ Engineering
An ALU has a multiplexer on the output so that you can choose which function to output.
The idea is that an ALU will receive an op code that determine which arithmetic function to compute. An ALU typically does Boolean logic functions along with add and subtract. ALU will actually compute ever function for the input A and B, but the op code will determine which to output. So this op code will be the select lines on your multiplexer.
Google basic digital logic, if you don't know how a multiplexer operates. You need to understand simple digital logic if you are going to attempt designing a processor
2006-10-08 15:34:17 · answer #1 · answered by cw 3 · 0⤊ 0⤋