Vector processor 9_ Basic multilevel interconnection network

Different multi-level interconnection networks , In the used Switching switch 、 Topology and control mode Each has its own difference .

One Switching switch It is a switching unit with two input terminals and two output terminals , It is used as the basic component of various multi-level interconnection networks . Both in and out , If you want all the people above to use i Express , Those below are used j Express , You can define the following 4 Switch state or connection mode ：

As shown in the figure ：

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Hanging here means disconnection , Out-of-service .

Only the first two functions are called two function switching units , A four function switching unit with all four functions . 

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Two   topology It is the mode of interconnection between the outgoing and incoming ends of all levels . 

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3、 ... and The control mode It is the way to control each switching switch , Take multistage cube network as an example , It can have 3 Kind of ：

1. Level control —— All switches at the same level are controlled by only one control signal , Can only be in the same state at the same time .
2. Unit control —— Each switch is controlled by its own independent control signal , Can be in different states .
3. Partial level control —— The first i All switches of the stage are used separately i+1 A signal control , 0<= i <= (n-1),n Is a series .

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1. Multistage cube network

Multistage cube networks have STARAN The Internet ( Staran )、 Indirect binary n Square network . With 8 Take a processing unit as an example , Its general structure is shown in the figure 6-18 Shown . Their common feature is ： The first i level (0<=i<=(n-1) ) When the switching unit is in the switching state , What we achieve is    Interconnection function , And both adopt two function switching units .  STARAN And indirect binary The difference is only in the way of control ,STARAN The network adopts level control ( Called switching network ) And partial level control ( Among them, the number shifting network that can realize the number shifting function ), And indirect binary n Unit control for square network . therefore , Indirect binary has greater connection flexibility .

 

2. Multistage shuffle switching network  

This network is also called omega The Internet ( Omega network ), Pictured 6-19 Shown . It consists of n The same level of network composition , Each level contains a fully mixed topology and a subsequent column   Four functional switching units , Adopt unit control mode . Compare pictures 6-18 Sum graph 6-19, You can find , omega The order of the numbers of all levels in the network is just the opposite to that of the multi-level Cube Network . If you put omega The incoming and outgoing positions of the network are exchanged , It is equivalent to indirect binary n Square network . therefore ,

omega Network and indirect binary n Square network has only two differences ：

• omega The network data flow direction is level number n-1, n-2, ...,1, 0 Use four function switching unit
• Indirect binary data flows in the opposite direction , It's a class number 0, 1, ..., n-1, Use two function switching unit .

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3. multistage PM2I The Internet

It includes ： Data transformation network (Data. Manipulator) , Strengthen data transformation (Augmented Data. Manipulator. ADM).

multistage PM2I The structure diagram of the network is complex , This article does not show .

4. Benchmark network

chart 6-21 It shows N=8 Benchmark network . It is similar to the inverse network of binary Cube Network , Just in the 1 The interstage connections of stages are different . It takes the interconnection between stages from input to output as identity 、 Inverse total mixing 、 Subinverse total mixing identity permutation , All switching units used are of two functions , Take unit control .

The reference network can be used as an intermediate medium in multi-level Networks , Simulate the topology and function of a network .