Periodic Bias-Temperature Instability monitoring in SRAM cells

A method and a circuitry for the periodic monitoring of the Bias-Temperature Instability (BTI) influence on SRAMs are presented in this paper. Periodic BTI monitoring provides the ability to predict failures in the memory operation, due to aging, and early react to avoid them. The proposed scheme is based on a simple, low silicon area overhead, differential ring oscillator that can be easily embedded in a typical SRAM without affecting the normal mode of operation.