Arithmetic circuits

About this section

Here you will be learning about arithmetic circuits from the ground up. In theory you can look at each unit independently, with the exception of the multipliers, which require you to know about carry-save adders, and some multipliers build upon the architecture of existing adders. But learning from adders to the FPU in that order feels natural, at least to me, and not jut because of difficulty. Multipliers build their architecture from adders. Similarly, dividers depend on subtraction. FPUs depend on adders and multipliers, as do systolic architectures and DSPs.

Why are we only learning about shifters later?

Barrel shifters differ from one another on a transistor level, even if almost all of the shifter architectures are implemented with pass transistors. If you’re writing HDL code, none of this matters to you, so the article will mostly be used just to sate your curiosity.

Adders

Multipliers

Dividers

Integer ALU outline

Floating point units

Systolic and Wavefront architectures

Warning: my master’s thesis is about systolic architectures. If there is some information that you can’t find anywhere else online, it’s probably because I made it the fuck up it’s something that I got out of my research.

Digital Signal Processors (DSPs)

Shifters