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Chapter 8  Constraints

Some operations of the main algorithm graph may be constrained to be executed on specific operators of the architecture graphs. In this case the heuristics will not have the choice in distributing them. These constraints are specified through operation groups. All the operations of an operation group will be distributed onto the same operator.

8.1  To create an operation group

To create a new operation group, from the Algorithm menu of the principal window, choose the Define Operation Group option. It opens a dialog window. Type the name of the new operation group. Then left click OK.

8.2  To attach references to operation groups

Figure 8.1: algo as main algorithm in examples/tutorial/example7/example7.sdx

From the main mode of the algorithm window (cf. section 5.1.2) left click on the target reference. In its Reference Properties (cf. Algorithm window in chapter 5) left click on the Group button and select the target operation group (cf. figure 8.1).

If it references a hierarchical definition, all the references of this hierarchy will be attached to this operation group (except references of this hierarchy that may be explicitly attached to another operation group).

In particular, in case of a reference to a conditioned (resp. repeated) definition its CondI and CondO (resp. Explode and Implode) vertices created by SynDEx when flattening the algorithm graph (cf. section 9.5). will be attached to the operation group.

8.3  To constraint operation groups on operators

Figure 8.2: Constraints on the main architecture in examples/tutorial/example7/example7.sdx

To constraint the references attached to a given operation group to be distributed onto a specific operator, you will constraint the operation groups on operators. From the Constraints menu, choose the Absolute Constraints option. Then, select the target architecture that will open a constraints window.

The Absolute Constraints on Main option does not allow you to choose the target architecture which, of course, is the architecture defined as main.

In the constraints window, left click on the target group in the left list to constraint an operation group on an operator, then left click on the target operator in the middle of the constraints window, and finally left click on the Create button. It adds the new constraint in the right list (cf. figure 8.2). Left click on the OK button to confirm your new constraint list, otherwise left click on the Cancel button.

8.4  To delete an operation group

To delete an operation group, from the Algorithm menu of the principal window, choose the Delete Operation Group option. It lists all the operation groups. Select the target group.

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