DRAFT : IEEE TRANSACTIONS ON COMPUTER - AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS , 2001 1 Pseudo Pin Assignment with Crosstalk

| This paper presents a new pseudo pin assignment (PPA) algorithm with crosstalk noise control in multi-layer gridless general-area routing. We propose a two-step approach that considers obstacles and minimizes the weighted sum of total wire length and the estimated number of vias under crosstalk noise constraints. We test our algorithms on a set of MCM examples and a set of standard cell examples. Without crosstalk noise control in PPA, the average noise in the MCM test cases after detailed routing is 0:13-0:22 V DD with up to 11% of nets larger than 0:3 V DD. However, if the noise constraint of each net is set to 0:3 V DD in PPA, the average noise in each case reduces to 0:11-0:15 V DD (15%-31% reduction) with no crosstalk noise violations. Most of the nets in our standard cell test cases do not have noise problems. Our PPA algorithms still give better noise distributions and have 1%-10% noise reduction on the global nets in these standard cell test cases. Even without rip-up and reroute, the detailed routing completion rate is 93%-99% and the average vias per net is only 0:7-1:4 for our MCM test cases and 1:0-1:7 for our standard cell test cases.