Intellectual property metering(4)

Abstract. We have developed the first hardware and software (intellectual property) metering scheme that enables reliable low overhead proofs for the number of manufactured parts and copied programs. The key idea is to make each design slightly different d

every possible solution which uses the minimal number of colors. The only difference is in terms of the control unit (FSM). Since the datapath is not modified, we can use the same mask for all layouts. The control unit is a very small fraction of the total layout area and we implement it by using a programmable technology such as EEPROM. The most appealing advantage of EEPROM is that it is not programmed during the mask steps, but can be later configured in a fast and cost effective way.

There are several ways how to produce solutions with identical datapaths and distinct control paths. For example, one option is to permute the subsets of variables that are assigned to particular register. There are n! solutions, when n registers are used in the reg-ister file for a set of variables. Another alternative is that by using degrees of freedom in assigning the variables to registers or by using redundant states for the same FSM and adding new constraints to find different control flows during the logic synthesis phase.

We illustrate the first option by adding dashed-lines on the graph in Figure 6. The example is the constructed from Figure 6 by adding one extra node, u1. The node v1 is connected to 3 other nodes (this is shown by the dash-lines on the figure). Since we are using 5 colors to color our graph (since 5 variables are simultaneously alive in control step 5 that is an minimal solution), we have a degree of freedom of 2 to color this node. In the previous section, we have used R1 to color this node, but now we see that we can also use R5 to color it. Note that the same effect can be done as preprocessing step as explained in Section 5.1

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V9Figure 3. The interval graph of the CFIIR filter

Figure 4. Datapath for the CFIIR filter