17-14
OVERDRIVE® PROCESSOR SOCKET SPECIFICATION
17.3.3.1.
OVERDRIVE
®
PROCESSOR CPUID
Following power-on RESET or the CPUID instruction, the EAX register contains the values
shown in Table 17-3.
17.3.3.2.
COMMON CAUSES OF UPGRADABILITY PROBLEMS DUE TO BIOS
CPU signature detection has been a common cause of current upgradability problems due to
BIOS. A few precautions within the BIOS can help to eliminate future upgradability problems
with Pentium Pro processor-based systems. When programming or modifying a BIOS, be aware
of the impact of future OverDrive processors. The following recommendations should prevent
problems in the future:
•
Always use the CPU signature and feature flags to identify the processor, including future
processors.
•
Never use timing loops for delays.
•
If an OverDrive processor is detected, report the presence of an “OverDrive processor” to
the end-user.
•
If an OverDrive processor is detected, don’t test on-chip cache sizes or organization. The
OverDrive processor cache parameters differ from those of the Pentium Pro processor.
•
If an OverDrive processor is detected, don’t use the Pentium Pro processor model specific
registers and test registers. OverDrive processor MSRs differ from those of the Pentium
Pro processor.
•
Memory Type Range Registers must be programmed as for a Pentium Pro processor.
17.4.
OVERDRIVE
®
PROCESSOR ELECTRICAL
SPECIFICATIONS
This section describes the electrical requirements for the OverDrive processor.
NOTE
ZIF socket electrical parameters may differ from LIF socket parameters;
therefore, be sure to use the appropriate ZIF socket parameters for electrical
design simulations.
Table 17-3. OverDrive
®
Processor CPUID
Type [13:12]
Family [11:8]
Model [7:4]
Stepping [3:0]
1
6
3
X
Summary of Contents for Pentium Pro Family
Page 17: ...1 Component Introduction ...
Page 26: ...2 Pentium Pro Processor Architecture Overview ...
Page 27: ......
Page 36: ...3 Bus Overview ...
Page 62: ...4 Bus Protocol ...
Page 105: ...5 Bus Transactions and Operations ...
Page 126: ...6 Range Registers ...
Page 131: ...7 Cache Protocol ...
Page 135: ...8 Data Integrity ...
Page 148: ...9 Configuration ...
Page 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Page 172: ...11 Electrical Specifications ...
Page 201: ...12 GTL Interface Specification ...
Page 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Page 233: ...14 Thermal Specifications ...
Page 239: ...15 Mechanical Specifications ...
Page 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Page 252: ...16 Tools ...
Page 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Page 264: ...17 OverDrive Processor Socket Specification ...
Page 290: ...A Signals Reference ...
Page 320: ...Index ...
Page 328: ......