Port controller for GALS with first come first served function

This paper describes port controllers that implements a first come first served scheme and are intended to be used in GALS systems. The port controllers described can handle handshake with or without stopping the local clock. It is also possible to stop the local clock until a handshake signal arrives to one of several ports. The port controllers described uses only standard cells to minimize the design effort when migrating between CMOS processes.