Microprocessor including an interrupt polling unit configured to poll external devices for interrupts when said microprocessor is in a task switch state

An interrupt polling unit included within a bus interface unit of a microprocessor is provided. The interrupt polling unit causes an interrupt acknowledge bus transaction to occur. If an interrupt controller receiving the interrupt acknowledge bus transaction returns an interrupt vector indicative of an interrupt service routine, then the microprocessor executes the interrupt service routine. The number of interrupt acknowledge bus transactions associated with the interrupt is reduced from two to one. In one embodiment, the interrupt polling unit causes an interrupt acknowledge bus transaction to occur when the microprocessor is performing a task switch. The task switch may be performed by hardware included within the microprocessor or, alternatively, by software executing upon the microprocessor.