A bus delay reduction technique considering crosstalk

As the CMOS technology scaled down, the horizontal coupling capacitance between adjacent wires plays a dominant part in wire load, crosstalk interference becomes a serious problem for VLSI design. We focused on the delay increase caused by crosstalk. On-chip bus delay is maximized by the crosstalk effect when adjacent wires simultaneously switch for opposite signal transition directions. This paper proposes a bus delay reduction technique by intentional skewing signal transition timing of adjacent wires. An approximated equation of bus delay shows our delay reduction technique is effective for a repeater-inserted bus. The result of SPICE simulation shows that the total bus delay reduction by from 5% to 20% can be achieved.