Three-Layer VLSI Channel Routing With Movable Terminals

[[abstract]]Abstract-A problem of wiring a channel of movable terminals in a VLSI chip is presented. Two subproblems are addressed, namely, maximum alignment and track assignment. Maximum alignment is to reassign terminal positions in the channel in order to maximize the number of nets that can be implemented as straight connections. Track assignment locates physicallythe interconnection of every net to the horizontal track in the channel. The two subproblemsare solved using two heuristic algorithms. Some well-known examples, including Deutsch's difficult example, are used as test cases to study our algorithms. The results show that both channel width and via usage are reduced significantly by using our procedures when comparing tothe routing with fixed terminals.