Paper Review: Buffer placement in distributed RC-tree networks for minimal Elmore delay

Abstract
This paper presents an algorithm for choosing the buffer positions for a wiring tree such that the "Elmore-delay" is minimal. For given required arrival times at the sinks of the wiring tree, the algorithm chooses buffers such that the required departure time at the source is as late as possible The topology of the wiring tree, a steiner tree, is assumed given, as well as the possible (legal) positions of the buffers. The algorithm uses a depth first search on the wiring tree to construct a set of time/capacitance pairs that correspond to different choices. The complexity of the algorithm is O(B^2) where B is the number of possible buffer positions. An extension of the asic algorithm allows minimization of the number of buffers as a secondary objective.

Paper Location
Google Scholar

Citation
[1] L. Van Ginneken, "Buffer placement in distributed RC-tree networks for minimal Elmore delay," Proc. IEEE Int. Symp. on Circuits and Systems, 1990, p. 865–868.

Positive

• Good use of distributed model for long wires
• Very clear algorithm description, lines are referenced in text to describe pieces of the algorithm more clearly!

Negative

• Poor formalization of the problem, lack of true mathematical rigor.
• No comparison against competing solutions or even the exact equations for runtime. Hard to say if this is a substantial improvement without them.