Monitoring and reconfiguration techniques for power supply variation tolerant on-chip links

We present a runtime power supply and temperature variation tolerance technique for delay-insensitive on-chip communication links. Signal integrity of a current sensing receiver is affected by runtime supply voltage and temperature fluctuations. By monitoring receiver´s input current and comparing it with receiver´s reference current, the effect of variation on link reliability is detected. Receiver reconfiguration and request for retransmission is carried out when error is detected. This scheme makes the link adaptive to the effect of variations enabling continuous and reliable operation of the link. The power consumption due to monitoring is 489μW for a 2mm link, which is 1.63% of a 64-bit l-of-4 encoded link´s power consumption. It requires only 5.83um additional active area. The circuits are designed and simulated in Cadence Analog Spectre using 65nm CMOS technology from STMicroelectronics.