AMD 10 User Manual

26237C—May 2003

The chipset samples the FID[3:0] signals in a chipset-specific
manner from the processor and uses this information to
determine the correct serial initialization packet (SIP). The
chipset then sends the SIP information to the processor for
configuration of the AMD Athlon system bus for the clock
multiplier that determines the processor frequency indicated
by the FID[3:0] code. The SIP is sent to the processor using the
SIP protocol. This protocol uses the PROCRDY, CONNECT, and
CLKFWDRST signals, that are synchronous to SYSCLK.

For more information about FID[3:0], see “FID[3:0] Pins” on
page 74.

Serial Initialization Packet (SIP) Protocol.  Refer to AMD Athlon™ and
AMD Duron™ System Bus Specification, order# 21902 for details
of the SIP protocol.

RESET# cannot be asserted to the processor without also being
asserted to the Northbridge. RESET# to the Northbridge is the
same as PCI RESET#. The minimum assertion for PCI RESET#
is one millisecond. Southbridges enforce a minimum assertion
of RESET# for the processor, Northbridge, and PCI of 1.5 to 2.0
milliseconds.