Interrupt branch address formed by concatenation of base address and bits corresponding to highest priority interrupt asserted and enabled

摘要

An interrupt service table pointer (ISTP) facilitates fast branching to interrupt service routines. An interrupt service table base (ISTB) field establishes a base address at which one or more routines reside in memory. A highest priority enabled interrupt (HPEINT) field identifies an interrupt to service. The concatenation of the ISTB, the HPEINT, and one or more least significant zeros points to the first instruction of a group of instructions which service a specific interrupt. The ISTB is user programmable. The HPEINT is automatically calculated each cycle by the data processor incorporating the ISTP.