1. A method of accessing registers, comprising: directly accessing a first set of registers; indirectly accessing a second set of registers via the first set of registers; and selecting one of a plurality of auto-change modes based on a first register of the first set of registers, wherein accessing the first register of the first set of registers sets a second register of the first set of registers to a predetermined value, wherein the plurality of auto-change modes comprises: an auto-increment mode in which a first address stored in the second register of the first set of registers is incremented at the completion of a bus cycle; an auto-decrement mode in which a first address stored in the second register of the first set of registers is decremented at the completion of the bus cycle; and an auto-reset mode in which the second register is set to a predetermined value at the completion of the bus cycle.