Buffers

There are two kinds of buffers related to RTL interconnects: the output buffer driving the output network for each DPU and the buffers (a.k.a. repeaters) inserted along a long wire to reduce its delay. One can also view the latter as a distributed output buffer. Buffers increase interconnect power consumption significantly. Studies show that the total switched capacitance of inserted buffers (repeaters) is about $1.1$ times the total switched capacitance of the corresponding wire [58] when buffer insertion is delay-optimized. For output buffers, it has been shown that their total switched capacitance is also approximately $1.1$ times that of the corresponding wire [59] (see Appendix for details). Therefore, we do not distinguish between these two kinds of buffers and treat them as an integral part of a wire in the following.