High-level synthesis techniques for functional test pattern execution

Functional debugging often dominates the time and cost of the ASIC system development, mainly due to the limited controllability and observability of the storage elements in designs, and therefore the intermediate variables in functional specifications. We propose a new divide-and-conquer approach for maximizing the simultaneous controllability of an arbitrary set of the user-selected variables in the design at the debugging time for facilitating the functional test pattern execution while minimizing the hardware overhead. The approach imposes minimal restriction on register sharing so that the synthesized designs will have the desired characteristic while minimizing the additional hardware overhead and minimizing the disruption of the optimization potential when scheduling, allocation and binding tasks in high-level synthesis are performed. The effectiveness of the proposed approach is demonstrated on a number of designs. (C) 1998 Elsevier Science B.V. All rights reserved.