ELEC 422 - Initial Design proposal

Group members : Abhinav Dubey, Todd Waterman , Indra Neel Datta

We have implemented an 8-bit ALU which executes AND, OR, NOT, ADD, and Square Root. All ALU functions execute on 2's complement numbers, although only positive numbers are valid inputs for the Square Root.

Our idea for the square root operation is to use an iterative algorithm such as:

S(n) = 0.5[S(n-1) + A/S(n-1)].

S(n-1) is an initial estimate of the square root of A. S(n) approaches S(n-1) as S(n-1) approaches square root of A.

All operations execute in a single cycle except the square root; however, the combinational square used by the square root also completes in one cycle.

This is a table of some of the operations that we plan to implement :

Mnemonic

Operation

ADD A Acc = Acc + A
SUB A Acc = Acc - A
AND A Acc = A && Acc
OR A Acc = A || Acc
LOAD A Acc = A
SQRT A Acc = sqrt(acc), A=initial estimate
NOT Acc = !Acc