Low-power current-mode transceiver for on-chip bidirectional buses

This paper presents a current-mode signalling scheme for bidirectional long on-chip interconnects. The transceiver has been fabricated in 180nm CMOS process. Features of the proposed scheme are driver pre-emphasis and low-impedance termination. While no extra repeater is needed for line lengths up to 8mm long the scheme improves the delay by 34% for 2mm-8mm long lines, compared to bidirectional voltage-mode links. The scheme also improves the power performance for line lengths longer than 2mm, operating at data rates higher than 180Mbps. Measurement results show that delay and power-delay product improve by 18% and 3.7×, respectively, compared to simulation results of the voltage-mode scheme.