Intel486™ And Pentium ® Processor Signatures; Feature Flags From Cpuid Instruction - Intel MultiProcessor Specification

Table 4-5. Intel486 and Pentium Processor Signatures
Family Model
0000 0000
0100 0000 and 0001
0100 0010
0100 0011
0100 0011
0100 0100
0100 0101
0100 1000
0101 0001
0101 0010
Values not shown are reserved for future processors.
Refer to the documentation of each new processor for its family and model values.
1111 1111
a Intel releases information about stepping numbers as needed.
Table 4-6. Feature Flags from CPUID Instruction
Bit Name Description
0 FPU On-chip Floating
Point Unit
1–6
7 MCE Machine Check
Exception
8 CX8 CMPXCHG8B
Instruction
9 APIC On-chip APIC
10–31
Version 1.4
a
Stepping
Description
0000 Not a valid CPU signature.
xxxx Intel486 DX Processor
xxxx Intel486 SX Processor
xxxx Intel487 Processor
xxxx IntelDX2™ Processor
xxxx Intel486 SL Processor
xxxx IntelSX2™ Processor
xxxx IntelDX4™ Processor
xxxx Pentium Processors (510\60, 567\66)
xxxx Pentium Processors (735\90, 815\100)
1111 Not a valid CPU signature. Indicates a processor that is not
an Intel architecture-compatible processor (a graphics
controller, for example)
Comments
The processor contains an FPU that supports the Intel387
processor floating point instruction set.
Reserved.
Exception 18 is defined for machine checks, including CR4.MCE for
controlling the feature. This feature does not define the model-
specific implementations of machine-check error logging reporting
and processor shutdowns. Machine-check exception handlers may
have to depend on processor version to do model-specific
processing of the exception or test for the presence of the standard
machine-check feature.
The 8 byte (64 bits) compare-and-exchange instruction is supported
(implicitly locked and atomic). Introduced by the Pentium
processor.
Indicates that an integrated APIC is present and hardware enabled.
(Software disabling does not affect this bit.)
Reserved.
MP Configuration Table
4-9