Enabling fine-grain leakage management by voltage anchor insertion

Functional unit shutdown based on MTCMOS devices is effective for leakage reduction in aggressively scaled technologies. However, the applicability of MTCMOS-based shutdown in a synthesis-based design flow poses the challenge of interfacing logic blocks in shutdown mode with active units: The outputs of inactive gates can float at intermediate voltages, causing very large short-circuit currents in the active gates they drive. In this paper, we propose two novel low-overhead elementary cells that fully address this issue. These cells can be added to any synthesis library, and they can be inserted into a netlist at the boundary between shutdown and active regions. Our results show that: (i) Our cells solve the interfacing problem with minimum overhead; (ii) A nonintrusive design flow enhancement is sufficient to automatically insert interface cells in post-synthesis netlists.

• Type: Conference
• Year: 2006
• Where: DATE
• Authors: Pietro Babighian, Luca Benini, Alberto Macii, Enrico Macii
• Keywords: DATE 2006, Functional Unit Shutdown, Hardware, Low-overhead Elementary Cells, MTCMOS-based Shutdown