Automated Technology Migration Methodology for Mixed-Signal Circuit Based on Multistart Optimization Framework

摘要

Optimization–simulation loop-based method is popular and efficient in design migration/reuse automation. However, it is only restricted to be used in block-level due to the complexity of current mixed-signal system. This paper presents a hierarchical methodology for efficiently migrating mixed-signal circuit design from one technology node to another, while keeping the same circuit and layout topologies. It utilizes two stages of optimization processes to automatically resize and refine device dimensions in target technology. In the first stage, to avoid the costly simulation time without scarifying systematical functionality, only one block is represented in transistor level (TL), while other blocks are replaced with behavioral models. The multistart global optimization technique is applied to resize the TL block in systematic connection. This stage provides a good initial point for next system-level refinement. Moreover, for obtaining a process and parasitic closure solution, both parasitic and process variation effects are explored and used to constrain the schematic migration. A representative mixed-signal system, charge-pump phase-locked loop, is used to validate the proposed methodology. The experimental results show that the proposed methodology efficiently generates quality designs in target technology with much less simulation iterations, when comparing with recent available approaches.