Specifications

PENTIUM® PRO PROCESSOR AT 150, 166, 180, and 200 MHz E
82
header must not interfere with the installation of the
Pentium Pro or OverDrive processors, and must not
interfere with the operation of the ZIF socket lever.
Alternately, Socket 8, and the installed processor
must not interfere with the installation and removal of
a VRM in Header 8.
NOTE
Components placed close to Socket 8 must
not impede access to and operation of the
handle of the ZIF socket lever. Adequate
clearance must be provided within the
proximity of the ZIF socket lever to provide
fingertip access to the lever for normal
operation, and to allow raising the lever to the
full open position.
8.2.2.3. Socket 8 Clip Attachment Tabs
Standardized clip attachment tabs will be provided on
Socket 8. These will allow clips to secure the
OverDrive processor to the socket to enhance shock
and vibration protection. OEMs may utilize the
attachment tabs for their own thermal solutions. As
an option, OEMs may use customized attachment
features providing that the additional features do not
interfere with the standard tabs used by the upgrade.
Details of the clip attachment tabs and overall
dimensions of Intel qualified sockets may be obtained
from participating socket suppliers.
8.2.3. OVERDRIVE
®
VOLTAGE REGULATOR
MODULE DEFINITION
Header 8 is a 2-row, 40-pin shrouded header
designed to accommodate a Pentium Pro processor
VRM, OverDrive VRM, or a programmable VRM. The
OverDrive VRM is used to convert the standard
5.0 V supply to the OverDrive processor core
operating voltage. Integral OverDrive VRM hold
down tabs are included as part of the header
definition for enhanced shock and vibration
protection.
OEMs who plan to design a custom VRM PC Board
to fit into Header 8 should refer to the AP-523,
Pentium
®
Pro Processor Power Distribution
Guidelines
Application Note (Order Number 242764).
8.2.3.1. OVERDRIVE
®
VRM Requirement
When upgrading with an OverDrive processor, Intel
suggests the use of its matched Voltage Regulator
Module, which Intel plans to ship with the OverDrive
processor retail package.
If the OEM includes on-board voltage regulation and
the Header 8 for the OverDrive VRM, the on-board
voltage regulator must be shut off via the UP# output
of the CPU. When the OverDrive processor is
installed, and the UP# signal is driven LOW, the on-
board VR must never power on. This will ensure that
there is no contention between the OverDrive VRM
and the on-board regulator.
8.2.3.2. OverDrive
®
VRM Location
It is recommended that Header 8 be located within
approximately 1 inch of Socket 8 to facilitate end
user installation. For optimum electrical performance,
the Header 8 should be as close as possible to
Socket 8. The location must not interfere with the
operation of the ZIF socket handle or heatsink
attachment clips. To allow system design flexibility,
Header 8 placement is optional, but it is
recommended that Header 8 NOT be placed on the
same side of the ZIF socket as the handle.
8.2.3.3. OverDrive
®
VRM Pinout
The OverDrive VRM pinout and pin description is
presented in Figure 49 and Table 31, respectively.
8.2.3.4. OverDrive
®
VRM Space
Requirements
Figure 50 describes the maximum OverDrive VRM
envelope. No part of the OverDrive VRM will extend
beyond the defined space.