A reliable high-speed bus employing low-swing signaling can be designed by encoding the bus to prevent cross-talk and provide error correction. In this paper, we present fundamental limits on the number of wires required to achieve joint crosstalk avoidance and error correction in on-chip buses. We propose a code construction that results in practical encoding and decoding schemes with the number of wires being within 35% of the fundamental limits. The proposed codes, when applied to a 10-mm 32-bit bus in a 0.13-?m CMOS technology with low-swing signaling, provide 2.14? speed-up and 27.5% energy savings without any loss in reliability.