Power ISA

Power ISA is the specification for how Power architecture processors are to behave. It dictates the machine instructions available, and exactly how they are to process given data.

There are two primary versions of the Power ISA that are of interest to PowerNV platforms:

• Version 2.07 (POWER8 / POWER8E)
• Version 3.0B (POWER9)

History

The Power ISA evolved from the PowerPC ISA which in turn was an evolution of the POWER ISA used by POWER1 and POWER2 chips.

POWER ISA → PowerPC ISA → Power ISA

When the Power ISA 3.0B specification lists all available instructions, it specifically mentions what version of which architecture introduced the instruction; this gives a fairly quick history of the ISA itself:

Key to Version column in Power ISA 3.0B instruction list

Code	Explanation
P1	Instruction introduced in the POWER Architecture.
P2	Instruction introduced in the POWER2 Architecture.
PPC	Instruction introduced in the PowerPC Architecture prior to v2.00.
v2.00	Instruction introduced in the PowerPC Architecture Version 2.00.
v2.01	Instruction introduced in the PowerPC Architecture Version 2.01.
v2.02	Instruction introduced in the PowerPC Architecture Version 2.02.
v2.03	Instruction introduced in the Power ISA Architecture Version 2.03.
v2.04	Instruction introduced in the Power ISA Architecture Version 2.04.
v2.05	Instruction introduced in the Power ISA Architecture Version 2.05.
v2.06	Instruction introduced in the Power ISA Architecture Version 2.06.
v2.07	Instruction introduced in the Power ISA Architecture Version 2.07.
v3.0	Instruction introduced in the Power ISA Architecture Version 3.0.
v3.0B	Instruction introduced in the Power ISA Architecture Version 3.0B.

External Links

• Power ISA at IBM OpenPOWER portal