- MIPS-X
MIPS-X is a
microprocessor andinstruction set architecture developed as a follow-on project to theMIPS architecture atStanford University by the same team that developed MIPS. The project, supported by the Defense Advanced ResearchProjects Agency, [1] 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 aworkstation CPU, and has mainly been seen inembedded designs based on chips designed by Integrated Information Technology for use indigital 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 byESS Technology Inc. ) as their central processor andMPEG-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. [ [ftp://reports.stanford.edu/pub/cstr/reports/csl/tr/86/289/CSL-TR-86-289.pdf hsc instruction] , MIPS-X Instruction Set and Programmer's Manual, p. 65.] On other platforms, this type of instruction is known asHalt and Catch Fire .References
External links
* [http://mos.stanford.edu/papers/mh_jssc_87.pdf The original MIPS-X paper] from Stanford.
* [http://www.nerd-out.com/forum/viewtopic.php?t=8110&view=previous&sid=bebb6ca649a8d810c29263bb72fd4182 Forum post explaining the IIT connection]
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