Integrated placement and skew optimization for rotary clocking

—The clock distribution network is a key component of any synchronous VLSI design. High power dissipation and pressure volume temperature-induced variations in clock skew have started playing an increasingly important role in limiting the performance of the clock network. Rotary clocking is a novel technique which employs unterminated rings formed by differential transmission lines to save power and reduce skew variability. Despite its appealing advantages, rotary clocking requires flip-flop locations to match predesigned clock skew on rotary clock rings. This requirement poses a difficult chicken-and-egg problem which prevents its wide application. In this paper, we propose an integrated placement and skew scheduling methodology to break this hurdle, making rotary clocking compatible with practical design flows. A network flow based flip-flop assignment algorithm and a cost-driven skew optimization algorithm are developed. We also present an integer linear programming formula...

• Type: Conference
• Year: 2006
• Where: DATE
• Authors: Ganesh Venkataraman, Jiang Hu, Frank Liu, Cliff C. N. Sze
• Keywords: Clock, Clock Skew, DATE 2006, Hardware, Rotary Clocking