Energy-efficient and reliable low-swing signaling for on-chip buses based on redundant coding

As technology scales toward deep submicron, on-chip communication on global interconnects is becoming increasingly slow and power-hungry with respect to computation. Therefore, low-swing signaling is viewed as a natural choice for future on-chip communication fabrics. Unfortunately, as signal swings are reduced, the effect of noise sources such as power supply noise, crosstalk and radiation induced effects, becomes more significant. This paper investigates how to deal with noise sources in an energy-aware fashion when designing on-chip low-swing signaling schemes. The basic idea is to exploit redundant coding to maintain high communication reliability even in a low signal-to-noise ratio regime. We compare several error correcting codes and error detecting codes with retransmission, spanning the tradeoff between coding, decoding and retransmission performance, energy and reliability. The analysis is performed in a realistic system-on-chip setting, focusing on an AMBA bus interface.