Testing of modules (such as Intellectual property (IP) cores) in integrated circuits (such as system on a chip units (SOCs)) in situations when different modules operate with different characteristics of a control signal. In an embodiment, another module (“subsystem module”) may be implemented to be tested with any of a multiple characteristics of a control signal, and a register which is programmable to generate a derived control signal of a desired characteristic from an original control signal, is provided. The derived control signal is provided to test the subsystem module. According to an aspect of the invention the desired characteristic may be determined, for example, to test a path between the two modules at the same speed as at which the path would be operated in a functional mode.