powerpc

PowerPC
PPC

   <processor, standard> (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} {workstations}.  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)