Port calling: a transformation for reducing I/O during multi-package functional partitioning

Partitioning a system among multiple input and output (I/O) pin limited packages is a widely researched and hard-to-solve problem. I previously (Proc. Int. Symp. on FPGA, pp. 27-34, 1997) described a new approach yielding large improvements, which partitioned functions rather than structure, and which used a single bus for all inter-package data transfer. In this paper, I describe an extension permitting arbitrary distribution of I/O among the packages, and highlight experiments demonstrating even further I/O reductions, as well as surprisingly improved performance, with nearly no penalty