Aging sensors for workload centric guardbanding in dynamic voltage scaling applications

BTI induced aging degradation threatens circuit reliability through circuit performance degradation. This degradation is strongly workload dependent and can result in unbalanced signal edge degradation as asymmetric aging. Three ring oscillator based asymmetric aging sensitive sensors are demonstrated in a 28nm low power/poly SiON CMOS technology. These sensors are shown to be capable of providing an adequate circuit guard band to account for signal edge degradation due to NBTI. A novel DVS workload centric monitor embedded with asymmetric aging sensitive sensors is proposed for aging and power trade-off assessment. The measured data indicates that signal edge degradation has a linear dependency on workload ratio. The impact of the dynamic voltage scaling workload profile on aging and power is experimentally studied with this aging monitor and allows the assessment assists to the modeling of aging margin relaxation.