1. A method of performing configuration or control of a hardware-based subsystem that includes multiple hardware registers that define multiple configurations of the hardware-based subsystem and that are connected to a processor via a system bus, the method comprising: providing together with the subsystem a configuration/control unit having a controller portion and a read-only storage portion storing multiple sets of configuration data, each of the sets of configuration data including configuration parameters for each of the multiple registers, and each of the sets of configuration data defining a respective one of the multiple configurations; and the configuration/control unit, in response to a single register write that identifies one of the sets of configuration data, encapsulating the multiple hardware registers by performing configuration, reconfiguration, initialization or control of the subsystem, and by including storing writing, the configuration parameters of the identified set of configuration data, from the read-only storage portion to each of the multiple registers of the hardware subsystem.