Specifications

Computer Architecture and Maintenance (G-Scheme-2014)
processor instead of a socketed type, Intel moved back to the socket design to reduce
the manufacturing cost—especially with the Celeron, which at that time was competing
on the low end with Socket 7 chips from AMD and Cyrix.
The Socket 370 (PGA-370) pinout is shown in Figure ..
Figure. Socket 370 (PGA-370) Pentium III/Celeron
pinout (top view).
The Celeron was gradually shifted over to PGA-370,
although for a time both were available. All Celeron processors at 333MHz and lower
were available only in the Slot 1 version. Celeron processors from 366MHz to 433MHz
were available in both Slot 1 and Socket 370 versions; all Celeron processors from
466MHz and up through 1.4GHz are available only in the Socket 370 version.
Starting in October 1999, Intel also introduced Pentium III processors with integrated
cache that plug into Socket 370. These use a packaging called flip chip pin grid array
(FC-PGA), in which the raw die is mounted on the substrate upside down. The slot
version of the Pentium III was more expensive and no longer necessary because of the
on-die L2 cache.
Note that because of some voltage changes and one pin change, many original Socket
370 motherboards do not accept the later FC-PGA Socket 370 versions of the Pentium
III and Celeron. Pentium III processors in the FC-PGA form have two RESET pins and
require VRM 8.4 specifications. Prior motherboards designed only for the older
versions of the Celeron are referred to as legacy motherboards, and the newer
motherboards supporting the second RESET pin and VRM 8.4 specification are referred
to as flexible motherboards. Contact your motherboard or system manufacturer for
information to see whether your socket is the flexible version. Some motherboards,
such as the Intel CA810, do support the VRM 8.4 specifications and supply proper
voltage, but without Vtt support the Pentium III processor in the FC-PGA package will
be held in RESET#. The last versions of the Pentium III and Celeron III use the Tualatin
core design, which also requires a revised socket to operate. Motherboards that can
handle Tualatin-core processors are known as Tualatin-ready and use different chipsets
from those not designed to work with the Tualatin-core processor. Companies that sell
upgrade processors offer products that enable you to install a Tualatin-core Pentium III
or Celeron III processor into a motherboard that lacks built-in Tualatin support.
Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)
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