NS320xx
Encyclopedia
The 320xx or NS32000 was a series of microprocessor
s 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 microcontroller
s.
(Additional system registers not listed.)
The instruction set was very much in the CISC
model, with 2-operand instructions, memory-to-memory operations, flexible addressing mode
s, and variable-length byte-aligned instruction encoding. Addressing modes could involve up to two displacements and two memory indirections per operand.
Unlike some other processors, autoincrement of the base register was not provided; the only exception was a "top of stack" addressing mode that would pop sources and push destinations. Uniquely, the size of the displacement was encoded in its most significant bits: 0, 10 and 11 preceded 7-, 14- and 30-bit signed displacements. (Although the processors were otherwise consistently little-endian, displacements in the instruction stream were stored in big-endian order.)
General purpose operands were specified using a 5-bit field. To this could be added an index byte (specifying the index register and 5-bit base address), and up to 2 variable-length displacements per operand.
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 FPU
s 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.
The 32032 was introduced in 1984. It was almost completely compatible, but featured a 32-bit data bus (although keeping the 24-bit address bus) for somewhat faster performance. There was also a 32008, which was a 32016 with a data bus cut down to 8-bits wide for low cost applications. It was philosophically similar to the MC68008, and equally unpopular.
National Semiconductor also produced related support chips like Floating Point Units (FPUs)
, Memory Management Units (MMUs)
, and Direct Memory Access (DMA)
controllers. With the full set plus memory chips and peripherals, it was feasible to build a 32-bit computer system capable of supporting modern multi-tasking operating systems, something that had previously been possible only on expensive minicomputers and mainframe
s.
In 1985, National Semi introduced the NS32332, which was a much improved version of the 32032. From the datasheet, the enhancements include "the addition of new dedicated addressing hardware (consisting of a high speed ALU, a barrel shifter and an address register), a very efficient increased (20 bytes) instruction prefetch queue, a new system/memory bus interface/protocol, increased efficiency slave processor protocol and finally enhancements of microcode." There was also a new NS32382 MMU, NS32381 FPU and the (very rare) NS32310 interface to a Weitek
FPA.
In the Spring of 1987, National Semi introduced the NS32532. Running at 20-, 25- & 30-MHz, the NS32532 was an improved NS32332 with an integrated MMU and improved memory performance. Interestingly, there wasn't a new FPU; the NS32532 used the existing NS323381. The NS32532 was the basis of one of the few fully realized "public domain" hardware projects (that is, resulting in an actual, useful machine running a real operating system, in this case Minix
or NetBSD
), the PC532
.
The Swordfish was the semi-mythical NS32732 (sometimes called NS32764), originally envisioned as the high performance successor to the NS32532. This program never came to the market, but derivatives aimed at embedded system
s arrived circa 1990 (along with versions of the older NS32000 line for low cost products such as the NS32GX32, NS32CG16, NS32FV16, NS32FX161 and NS32FX164). These processors had some success in the laser printer
and fax
market, despite intense competition from AMD and Intel RISC chips.
Datasheets exist for an NS32132, apparently designed for multiprocessor systems, but there is no evidence that the processor was ever produced.
None of these are related to the National Semiconductor
NS32000 series.
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
s from National Semiconductor
National Semiconductor
National Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
("NS", "Natsemi"). They were likely the first 32-bit
32-bit
The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
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 microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
s.
Architecture
The processors had 8 general purpose 32-bit registers, plus a series of special-purpose registers:- Frame pointer
- Stack pointer (one each for user and supervisor modes)
- Static base register, for referencing global variables
- Program counter
- A typical processor status register, with a low-order user byte and a high-order system byte.
(Additional system registers not listed.)
The instruction set was very much in the CISC
Complex instruction set computer
A complex instruction set computer , is a computer where single instructions can execute several low-level operations and/or are capable of multi-step operations or addressing modes within single instructions...
model, with 2-operand instructions, memory-to-memory operations, flexible addressing mode
Addressing mode
Addressing modes are an aspect of the instruction set architecture in most central processing unit designs. The various addressing modes that are defined in a given instruction set architecture define how machine language instructions in that architecture identify the operand of each instruction...
s, and variable-length byte-aligned instruction encoding. Addressing modes could involve up to two displacements and two memory indirections per operand.
Unlike some other processors, autoincrement of the base register was not provided; the only exception was a "top of stack" addressing mode that would pop sources and push destinations. Uniquely, the size of the displacement was encoded in its most significant bits: 0, 10 and 11 preceded 7-, 14- and 30-bit signed displacements. (Although the processors were otherwise consistently little-endian, displacements in the instruction stream were stored in big-endian order.)
General purpose operands were specified using a 5-bit field. To this could be added an index byte (specifying the index register and 5-bit base address), and up to 2 variable-length displacements per operand.
Beginnings: the 32016 and 32032
The original 32016 had a 16-bit external databus, a 24-bit external address bus
Address bus
An address bus is a computer bus that is used to specify a physical address. When a processor or DMA-enabled device needs to read or write to a memory location, it specifies that memory location on the address bus...
, and a full 32-bit instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
. It also included a coprocessor
Coprocessor
A coprocessor is a computer processor used to supplement the functions of the primary processor . Operations performed by the coprocessor may be floating point arithmetic, graphics, signal processing, string processing, or encryption. By offloading processor-intensive tasks from the main processor,...
interface which allows coprocessors such as FPU
Floating point unit
A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
s and MMUs
Memory management unit
A memory management unit , sometimes called paged memory management unit , is a computer hardware component responsible for handling accesses to memory requested by the CPU...
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
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
instruction set. The 32016 was also very similar to the Motorola 68000
Motorola 68000
The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...
, which also used 32-bit internals with a 16-bit data bus and 24-bit address bus.
The 32032 was introduced in 1984. It was almost completely compatible, but featured a 32-bit data bus (although keeping the 24-bit address bus) for somewhat faster performance. There was also a 32008, which was a 32016 with a data bus cut down to 8-bits wide for low cost applications. It was philosophically similar to the MC68008, and equally unpopular.
National Semiconductor also produced related support chips like Floating Point Units (FPUs)
Floating point unit
A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
, Memory Management Units (MMUs)
Memory management unit
A memory management unit , sometimes called paged memory management unit , is a computer hardware component responsible for handling accesses to memory requested by the CPU...
, and Direct Memory Access (DMA)
Direct memory access
Direct memory access is a feature of modern computers that allows certain hardware subsystems within the computer to access system memory independently of the central processing unit ....
controllers. With the full set plus memory chips and peripherals, it was feasible to build a 32-bit computer system capable of supporting modern multi-tasking operating systems, something that had previously been possible only on expensive minicomputers and mainframe
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s.
The 32332, 32532, Swordfish & Others
During the 1980s, successor chips called the NS32332 and NS32532 arrived, maintaining a good degree of compatibility, with much improved reliability and performance. By then the damage to reputation had been done, however, and these chips were (probably unjustly) ignored by most of the market.In 1985, National Semi introduced the NS32332, which was a much improved version of the 32032. From the datasheet, the enhancements include "the addition of new dedicated addressing hardware (consisting of a high speed ALU, a barrel shifter and an address register), a very efficient increased (20 bytes) instruction prefetch queue, a new system/memory bus interface/protocol, increased efficiency slave processor protocol and finally enhancements of microcode." There was also a new NS32382 MMU, NS32381 FPU and the (very rare) NS32310 interface to a Weitek
Weitek
Weitek Corporation was a chip-design company that originally concentrated on floating point units for a number of commercial CPU designs. During the early to mid-1980s, Weitek designs could be found powering a number of high-end designs and parallel processing supercomputers...
FPA.
In the Spring of 1987, National Semi introduced the NS32532. Running at 20-, 25- & 30-MHz, the NS32532 was an improved NS32332 with an integrated MMU and improved memory performance. Interestingly, there wasn't a new FPU; the NS32532 used the existing NS323381. The NS32532 was the basis of one of the few fully realized "public domain" hardware projects (that is, resulting in an actual, useful machine running a real operating system, in this case Minix
Minix
MINIX is a Unix-like computer operating system based on a microkernel architecture created by Andrew S. Tanenbaum for educational purposes; MINIX also inspired the creation of the Linux kernel....
or NetBSD
NetBSD
NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
), the PC532
PC532
The PC532 was a "home-brew" microcomputer design created by George Scolaro and Dave Rand in 1989-90, based around the National Semiconductor NS32532 microprocessor...
.
The Swordfish was the semi-mythical NS32732 (sometimes called NS32764), originally envisioned as the high performance successor to the NS32532. This program never came to the market, but derivatives aimed at embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s arrived circa 1990 (along with versions of the older NS32000 line for low cost products such as the NS32GX32, NS32CG16, NS32FV16, NS32FX161 and NS32FX164). These processors had some success in the laser printer
Laser printer
A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...
and fax
Fax
Fax , sometimes called telecopying, is the telephonic transmission of scanned printed material , normally to a telephone number connected to a printer or other output device...
market, despite intense competition from AMD and Intel RISC chips.
Datasheets exist for an NS32132, apparently designed for multiprocessor systems, but there is no evidence that the processor was ever produced.
Machines Using the NS32000 Series
An few example machines using NS32000-series CPUs:- Acorn Cambridge Workstation - NS32016 (with 6502 host)
- BBC MicroBBC MicroThe BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by Acorn Computers for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation...
- NS32016 Second Processor http://wouter.bbcmicro.net/bbc/32016/index.html http://www.beebmaster.co.uk/Cambridge2.html http://www.binarydinosaurs.co.uk/Museum/Acorn/32016copro/index.php - WhitechapelWhitechapel Computer WorksWhitechapel Computer Works Ltd. was a computer workstation company formed in the East End of London, United Kingdom in April 1983, with investment from the Greater London Enterprise Board and the Department of Trade and Industry....
MG-1 - NS32016 - Whitechapel MG200 - NS32332
- Opus - NS16032 PC Add-On Board
- SequentSequent Computer SystemsSequent Computer Systems, or Sequent, was a computer company that designed and manufactured multiprocessing computer systems. They were among the pioneers in high-performance symmetric multiprocessing open systems, innovating in both hardware and software Sequent Computer Systems, or Sequent, was...
Balance - NS32016, NS32032 & NS32332 Multiprocessor - ETH Zurich CeresCeres (workstation)-Ceres Workstation:As a followup project to the Lilith, a machine based on bit-slice technology and the programming language Modula-2, Niklaus Wirth's group started around 1985 another workstation project based on the NS320xx CPU by National Semiconductor...
workstation - NS32532 - Heurikon VME532 - NS32532 VME Card (with cache)
- PC532PC532The PC532 was a "home-brew" microcomputer design created by George Scolaro and Dave Rand in 1989-90, based around the National Semiconductor NS32532 microprocessor...
- NS32532 - Tolerant Systems Eternity Series - NS32032 w/ NS32016 I/O processor
- National SemiconductorNational SemiconductorNational Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
ICM-3216 - NS32016 - National SemiconductorNational SemiconductorNational Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
ICM-332-1 - NS32332 w/ NS32016 I/O processor - National SemiconductorNational SemiconductorNational Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
SYS32/20 - NS32016 PC Add-On Board w/ Unix - EncoreEncore ComputerEncore Computer was an early pioneer in the parallel computing market, based in Marlborough, Massachusetts. Although offering a number of system designs beginning in 1985, they were never as well known as other companies in this field such as Pyramid Technology, Alliant, and the most similar...
Multimax - NS32332 & NS32532 Multiprocessor - Trinity College Workstation - NS32332
- Tektronix 6130 & 6250 Workstation - NS32016 & NS32032
- SiemensSiemens AGSiemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
PC-MX2 - NS32016 - Siemens MX300-05/-10/-15/-30 - NS32332 (-05/-10) or NS32532 (-15/-30) under SINIXSINIXSINIX was a variant of the Unix operating system from Siemens Nixdorf Informationssysteme. Supersedes SIRM OS and Pyramid Technology's DC/OSx. Its last release under the SINIX name was version 5.43 in 1995...
(MX300-55 and later use i486Intel 80486The Intel 80486 microprocessor was a higher performance follow up on the Intel 80386. Introduced in 1989, it was the first tightly pipelined x86 design as well as the first x86 chip to use more than a million transistors, due to a large on-chip cache and an integrated floating point unit...
) - Siemens MX500-75/-85 - NS32532 (2-8x CPUs; Sequent Boards / MX500-90 uses 2-12x i486)
- CompuproBill GodboutBill Godbout was an early computer pioneer and entrepreneur known for manufacturing and selling computer equipment, parts and Electronic kits in Silicon Valley, before the time of the Apple II....
32016 - NS32016 S-100 Card - Symmetric Computer Systems S/375http://jolitz.telemuse.net/william/symmetric - NS32016, used to cross develop 386BSD386BSD386BSD, sometimes called "Jolix", was a free Unix-like operating system based on BSD, first released in 1992. It ran on PC compatible computer systems based on the Intel 80386 microprocessor...
- General Robotics Corp. Python - NS32032 & N32016 Q-BusQ-BusThe Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....
Card - TeklogixTeklogix-About The Company:Teklogix was created in 1967 by Lawrence Cragg together with a small group of engineers.The company focused on mini computer applications. It designed and built complete systems based upon DEC's PDP-8 computer, DEC's logic modules and purpose built logic...
9020 network controller - NS32332 - Labtam 32032
Similarly named non-NS processors
The use of some variation on the number "32" was the obvious naming scheme for any series of 32-bit microprocessors. This leads to a certain amount of confusion and totally unrelated processors with similar names. For example:- There was the WE32xxx microprocessor series made by Western ElectricWestern ElectricWestern Electric Company was an American electrical engineering company, the manufacturing arm of AT&T from 1881 to 1995. It was the scene of a number of technological innovations and also some seminal developments in industrial management...
. This chipset was used in the AT&TAT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
3B23B ComputersThe 3B series computers were a line of micro-programmable minicomputers produced by AT&T Computer Systems's Western Electric subsidiary.-High-availability processors:The original series of 3B computers include the models 3B20C, 3B20D, 3B21D, and 3B21E....
series of minicomputers. - A very widespread series of DSPs by Texas InstrumentsTexas InstrumentsTexas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
is the TMS320Texas Instruments TMS320Texas Instruments TMS320 is a blanket name for a series of digital signal processors from Texas Instruments. It was introduced on April 8, 1983 through the TMS32010 processor, which was then the fastest DSP on the market....
line (starting with the TMS32010).
None of these are related to the National Semiconductor
National Semiconductor
National Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
NS32000 series.