Patent ID: 7769937

Claim:
A data processing system, comprising: a first interrupt controller, comprising: an interrupt source interface operable to receive interrupt requests generated by a first plurality of interrupt sources; an interrupt controller interface couplable to an output of a second interrupt controller to receive a second single interrupt request, selected by the second interrupt controller at least among interrupt requests generated by a second plurality of interrupt sources, a second priority signal associated with said selected second interrupt request, and a second interrupt source index signal associated with the source of said selected second interrupt request; prioritizing means arranged to select among said interrupt requests generated by said first plurality of interrupt sources and said selected second interrupt request, a first single interrupt request having highest priority; a first interrupt controller output operable to provide said selected first interrupt request; a first priority signal associated with said selected first interrupt request; a first index signal associated with the source of said selected first interrupt request; and a processing unit providing an interrupt controller interface couplable to said first interrupt controller output to receive the selected first interrupt request, the first priority signal, and the first index signal, said processing unit on a basis of said first index signal being operable to initiate an appropriate interrupt service routine.