A microprocessor including unprime registers for use during normal operation, prime registers for use during interrupts, a normal register set for use during normal operation and conventional interrupt operations, an alternate register set for use during fast interrupt operations, and a memory stack. Three status bits are used to indicate that one or more fast interrupts have been initiated but not completed, that a fast interrupt is occurring but there are no other fast interrupts being processed, and that the CPU is currently processing a fast interrupt. These status bits indicate if there is a recursion jeopardy and are used to control the flow of information between the normal and alternate register sets and the memory stack in order to prevent recursion.