1. An on-system programmable and off-system programmable chip comprising: a control circuit; an off-system programmable nonvolatile memory connected to said control circuit for being programmable only when connected to an external programming voltage; an on-system programmable nonvolatile memory connected to said control circuit for being programmable under control of said control circuit; a pumping circuit connected to said on-system programmable nonvolatile memory for supplying an internal programming voltage during programming said on-system programmable nonvolatile memory; a volatile memory connected to said control circuit; and an I/O unit connected to said control circuit.