Coding schemes for chip-to-chip interconnect applications

Increasing demand for high-speed interchip interconnects requires faster links that consume less power. The Shannon limit for the capacity of these links is at least an order of magnitude higher than the data rate of the current state-of-the-art designs. Channel coding can be used to approach the theoretical Shannon limit. Although there are numerous capacity-approaching codes in the literature, the complexity of these codes prohibits their use in high-speed interchip applications. This work studies several suitable coding schemes for chip-to-chip communication and backplane application. These coding schemes achieve 3-dB coding gain in the case of an additive white Gaussian noise (AWGN) model for the channel. In addition, a more realistic model for the channel is developed here that takes into account the effect of crosstalk, jitter, reflection, inter-symbol interference (ISI), and AWGN. Interestingly, the proposed signaling schemes are significantly less sensitive to such interference. Simulation results show coding gains of 5-8 dB for these methods with three typical channel models. In addition, low-complexity decoding architectures for implementation of these schemes are presented. Finally, circuit simulation results confirm that the high-speed implementations of these methods are feasible.