MIPS-X
Encyclopedia
MIPS-X is a microprocessor
and instruction set architecture developed as a follow-on project to the MIPS architecture
at Stanford University
by the same team that developed MIPS. The project, supported by the Defense Advanced Research Projects Agency, started in 1984, and its final form was described in a set of papers released in 1986–87. Unlike its older cousin, MIPS-X was never commercialized as a workstation
CPU, and has mainly been seen in embedded
designs based on chips designed by Integrated Information Technology for use in digital video
applications.
MIPS-X, while designed by the same team and architecturally very similar, is not instruction-set compatible with the mainline MIPS R-series processors. The processor is obscure enough that (as of this writing) support for it is provided only by specialist developers (such as Green Hills Software
), and is notably missing from GCC
.
MIPS-X has become important among DVD player
firmware
hackers, since many low-end DVD players use chips based on the IIT design (and produced by ESS Technology Inc.) as their central processor and MPEG-2
decoder.
The Programmer's Manual described an instruction called hsc, which means halt and spontaneously combust. The manual claimed that on the NSA versions of the processor, this instruction was executed when a protection violation was detected, however this was intended as a joke. On other platforms, this type of instruction is known as Halt and Catch Fire
.
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...
and instruction set architecture developed as a follow-on project to the MIPS architecture
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
by the same team that developed MIPS. The project, supported by the Defense Advanced Research Projects Agency, started in 1984, and its final form was described in a set of papers released in 1986–87. Unlike its older cousin, MIPS-X was never commercialized as a workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
CPU, and has mainly been seen in embedded
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...
designs based on chips designed by Integrated Information Technology for use in digital video
Digital video
Digital video is a type of digital recording system that works by using a digital rather than an analog video signal.The terms camera, video camera, and camcorder are used interchangeably in this article.- History :...
applications.
MIPS-X, while designed by the same team and architecturally very similar, is not instruction-set compatible with the mainline MIPS R-series processors. The processor is obscure enough that (as of this writing) support for it is provided only by specialist developers (such as Green Hills Software
Green Hills Software
Green Hills Software is a privately owned company that builds operating systems and development tools for embedded systems. The company was founded in 1982 by Dan O'Dowd and Carl Rosenberg...
), and is notably missing from GCC
GNU Compiler Collection
The GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...
.
MIPS-X has become important among DVD player
DVD player
A DVD player is a device that plays discs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. These devices were invented in 1997 and continue to thrive...
firmware
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...
hackers, since many low-end DVD players use chips based on the IIT design (and produced by ESS Technology Inc.) as their central processor and MPEG-2
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...
decoder.
The Programmer's Manual described an instruction called hsc, which means halt and spontaneously combust. The manual claimed that on the NSA versions of the processor, this instruction was executed when a protection violation was detected, however this was intended as a joke. On other platforms, this type of instruction is known as Halt and Catch Fire
Halt and Catch Fire
Halt and Catch Fire, known by the mnemonic HCF, refers to several computer machine code instructions that cause the CPU to cease meaningful operation...
.
External links
- The original MIPS-X paper from Stanford.