Area Efficient Functional Locking through Coarse Grained Runtime Reconfigurable Architectures

Abstract

The protection of Intellectual Property (IP) has emerged as one of the most important issues in the hardware design industry. Most VLSI design companies are now fabless and need to protect their IP from being illegally distributed. One of the main approach to address this has been through logic locking. Logic locking prevents IPs from being reversed engineered as well as overbuilding the hardware circuit by untrusted foundries. One of the main problem with existing logic locking techniques is that the foundry has full access to the entire design including the logic locking mechanism. Because of the importance of this topic, continuous more robust locking mechanisms are proposed and equally fast new methods to break them appear. One alternative approach is to lock a circuit through omission. The main idea is to selectively map a portion of the IP onto an embedded FPGA (eFPGA). Because the foundry does not have access to the bitstream, the circuit cannot be used until programmed by the legitimate user. One of the main problems with this approach is the large overhead in terms of area and power, as well as timing degradation. Area is especially a concern for price sensitive applications. To address this, in this work we presents a method to map portions of a design onto a Coarse Grained Runtime Reconfigurable Architecture (CGRRA) such that multiple parts of a design can be hidden onto the CGRRA, substantially amortizing the area overhead introduced by the CGRRA.