High-Vt, Low-Vt, Standard-Vt. Used to implement multi-threshold low power techniques. info
- HVT: less power, worse timing, used for power critical functions.
- LVT: more power, better timing, used in timing critical functions
- SVT: offers tradeoff between LVT and HVT
Subthreshold condution is one component of leakage. The amount of subthreshold conduction is set by the threshold voltgage, which sits between ground and the supply voltage.
From Multi-channel length:
Short channel length provide higher performance than longer channel lenghts, but longer channel lenghts has reduced subthreshold leakage current.
Timing critical paths are constructed of short channel length cells. Longer channel length cells can be used for non-timing-critical paths.
Timing corners:
- SS: NMOS slow, PMOS slow
- FF: NMOS fast, PMOS fast
- TT: NMOS typical, PMOS typical
NLDM vs. CSS Delay models: http://www.paripath.com/blog/characterization-blog/comparing-nldm-and-ccs-delay-models
Characterization split into four groups:
- pg: power gating cell
- ulvl: high-low level shifters
- dlvl: low-high level shifters
- others