G22.2233 - Prof. Grishman

Lecture 5: Arithmetic and ALU Design

Representing signed numbers (text, section 4.2 - 4.3)

MIPS ALU (text, section 4.5)

An ALU (arithmetic-logical unit) is a combinational circuit capable of computing a variety of arithmetic and logical functions.

Carry look-ahead (text, section 4.5)

We can speed up addition by introducing notion of "carry generate" and "carry propagate": We get greater savings when we build a 16-bit adder, and compute group generate and propagate values for each 4-bit group. Note that group values are designated by capital letters. Spring 2002