The 8×8 Omega Multistage Interconnection Network has the following structure:

Each rectangle is a 2×2 Banyan switch

The output xyz (3 bits) is connected to the input yzx (left rotated):

Example 1:   output 000 is connected to input 000

The output xyz (3 bits) is connected to the input yzx (left rotated):

Example 2:   output 001 is connected to input 010

The output xyz (3 bits) is connected to the input yzx (left rotated):

Example 3:   output 011 is connected to input 110 --- and so on...

The connection pattern is made in all 3 stages of the Omega network:

(We call this pattern a "perfect shuffle")

Example:   CPU 1 wants to access memory module 4 (binary 100):

The connection request will first arrive in the 2nd Banyan switch in layer 1...

The request 100 will set up the following connection in the Banyan switch:

And the remainder (00) is forwarded to the next switch...

The request 00 will set up the following connection in the Banyan switch:

And the remainder (0) is forwarded to the next switch...

The request 0 will set up the following connection in the Banyan switch:

And the path is set up !!!

The Omega network sorts the requests as follows:

The principle is the same as the Delta switch !

The interconnection pattern of each stage is the same:

Manifacturing the same connection pattern is very easy
(Chips are manufactured using a process called Photolithography)