Architectures and techniques that allow legacy pin functionality to be replaced with a “virtual wire” that may communicate information that would otherwise be communicated by a wired interface. A message may be passed between a system controller and a processor that includes a virtual wire value and a virtual wire change indicator. The virtual wire value may include a signal corresponding to one or more pins that have been eliminated from the physical interface and the virtual wire change value may include an indication of whether the virtual wire value has changed. The combination of the virtual wire value and the virtual wire change indicator may allow multiple physical pins to be replaced by message values.