Scalable Processor Architecture (SPARC)

Scalable Processor Architecture, better knwon as SPARC, is a reduced instruction set computing architecture (RISC) technology for microprocessors developed by Sun Microsystems, which introduced it in 1987. It is generally identified with the Solaris OS. The SPARC architecture is designed to optimize both 32-bit and 64-bit implementations.

SPARC is a highly-scalable open architecture designed to offer fast execution rates. The word "scalable" in SPARC means the register stack can be scaled up to 512, or 32 windows, to minimize processor loads. It can also be scaled down to minimize interference and context switching time. At some point during a function call, the window is passed 16 registers down the stack to share upper and lower registers between functions. The window is again moved up, pushing the local registers to the top or bottom of the stack, allowing local values to be maintained across function calls.

Since its release, there have been several revisions to the SPARC architecture. SPARC has introduced many new features in version 8, which includes multiply and divide functionality and a 128-bit quad-precision register.

In addition to Sun’s own Solaris, OpenSolaris and SunOS, SPARC is designed to support other OSs such as NetBSD, OpenBSD and Linux, among others.