Methodologies and tools for pipelined on-chip interconnect

Abstract

As processes shrink, gate delay improves much faster than the delay in long wires. Therefore, the long wires increasingly determine the maximum clock rate, and hence performance, of more and more chips. One solution to this problem is to pipeline the global interconnect, enabling the whole chip to run at the speed of local operations. While known to work well, this optimization is seldom used because of practical difficulties - it is hard to change the RTL, test vectors become invalid, and it's hard to prove correctness of any changes. Here we look at some ways these difficulties could be overcome.