Chapter 28. Pentium^® II Software Enhancements

The Previous Chapter

This chapter provided a detailed description of the power management modes found in all IA32 processors starting with the Pentium® II processor. Note that the Pentium® M processor added one additional mode, Deeper Sleep, and a description can be found in “Enhanced Power Management Characteristics” on page 1429.

This Chapter

This chapter provides a detailed description of the software enhancements first implemented in the Pentium® II processor. This discussion is directly applicable to all subsequent IA32 processors. This includes:

• The Pentium® II and Pentium® III MSRs.

• The Fast System Call/Return Instruction Pair.

• The FP/SSE Save/Restore Instruction Pair.

• New/Altered Exceptions.

The Next Chapter

This chapter describes the first Xeon processor. It was based on the Pentium® II processor. This includes:

• The Cartridge.

• FSB Protocol Alteration (GTL+ to AGTL+).

• FSB Arbitration.

• SMBus (System Management Bus). This is an introduction to the SMBus. A detailed description of the SMBus is outside the scope of this book.

• PSE-36 Mode. This discussion is directly applicable to all subsequent IA32 processors.