PowerPC processors, which will run the same code. The PowerPC
architecture is based on the IBM
POWER architecture, used in
The PowerPC standard specifies both 32-bit and 64-bit data
paths. Early implementations were 32-bit (e.g.
PowerPC601); later higher-performance implementations were 64-bit
(e.g. PowerPC 620). A PowerPC has 32 integer
registers (32-
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:
Control of branch prediction direction.
A hardware coherency model (not in Book I).
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).
(press releases), "Apple Technologies/" and "Product
General News/", "IBM Product Announcements/", "IBM Detailed
Product Announcements/", "IBM Hardware Catalog/".
["Microprocessor Report", 16 October 1991].
(1994-09-30)