Powerpc

1 definition found

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  PowerPC
       
           (PPC) A {RISC} {microprocessor} designed
          to meet a {standard} which was jointly designed by {Motorola},
          {IBM}, and {Apple Computer} (the PowerPC Alliance).  The
          PowerPC standard specifies a common {instruction set


          architecture} (ISA), allowing anyone to design and fabricate
          PowerPC processors, which will run the same code.  The PowerPC
          architecture is based on the IBM {POWER} architecture, used in
          IBM's {RS/6000} {workstation}s.  Currently {IBM} and
          {Motorola} are working on PowerPC chips.
       
          The PowerPC standard specifies both 32-bit and 64-bit data
          paths.  Early implementations were 32-bit (e.g. {PowerPC
          601}); later higher-performance implementations were 64-bit
          (e.g. PowerPC 620).  A PowerPC has 32 integer {registers} (32-
          or 64 bit) and 32 {floating-point} (IEEE standard 64 bit)
          {floating-point} registers.
       
          The POWER CPU chip and PowerPC have a (large) common core, but
          both have instructions that the other doesn't.  The PowerPC
          offers the following features that POWER does not:
       
          Support for running in {little-endian} mode.
       
          Addition of single precision {floating-point} operations.
       
          Control of branch prediction direction.
       
          A hardware coherency model (not in Book I).
       
          Some other {floating-point} instructions (some optional).
       
          The real time clock (upper and lower) was replaced with the
          time base registers (upper and lower), which don't count in
          sec/ns (the decrementer also changed).
       
          64-bit instruction operands, registers, etc. (in 64 bit
          processors).
       
          See also {PowerOpen}, {PowerPC Platform} (PReP).
       
          {IBM PPC info
          (http://fnctsrv0.chips.ibm.com/products/ppc/index.html)}.
       
          {(gopher://info.hed.apple.com/)}, "Apple Corporate News/"
          (press releases), "Apple Technologies/" and "Product
          Information/".  {(gopher://ike.engr.washington.edu/)}, "IBM
          General News/", "IBM Product Announcements/", "IBM Detailed
          Product Announcements/", "IBM Hardware Catalog/".
       
          {Usenet} newsgroups: {news:comp.sys.powerpc},
          {news:comp.sys.mac.hardware}.
       
          ["Microprocessor Report", 16 October 1991].
       
          (1994-09-30)