The
320xx or
NS32000 is a series of
microprocessors from
National Semiconductor ("NS", "Natsemi"). They were likely the first
32-bit general-purpose microprocessors on the market, but due to a number of factors never managed to become a major player. The 320xx series was also used as the basis of the
Swordfish series of
microcontrollers.
The first chip in the series was originally called 16032, later renamed 32016 to emphasize its 32-bit internals. It became available in the late 1970s, and may have been the first 32-bit chip to reach mass production and sale (at least according to National Semiconductor marketing).
The original 32016 had a 16-bit external databus, a 24-bit external address bus, and a full 32-bit instruction set. It also included a coprocessor interface which allows coprocessors such as FPUs and MMUs to be attached as peers to the main processor.
The instruction set was extremely complex but mostly regular, with a large set of addressing modes. It was somewhat similar in spirit to (but not compatible with) the popular DEC VAX minicomputer instruction set. The 32016 was also very similar to the Motorola 68000, which also used 32-bit internals with a 16-bit data bus and 24-bit address bus.
