AMD Athlon 27493 - Manual (Page 85)

Chapter 11 Pin Descriptions 73
26237C—May 2003 AMD Athlon™ XP Processor Model 10 Data Sheet
Preliminary Information
CLKIN, RSTCLK
(SYSCLK) Pins Connect CLKIN with RSTCLK and name it SYSCLK. Connect
CLKIN# with RSTCLK# and name it SYSCLK#. Length match
the clocks from the clock generator to the Northbridge and
processor.
See “SYSCLK and SYSCLK#” on page 77 for more information.
CONNECT Pin CONNECT is an input from the system used for power
management and clock-forward initialization at reset.
COREFB and
COREFB# Pins COREFB and COREFB# are outputs to the system that provide
processor core voltage feedback to the system.
CPU_PRESENCE# Pin CPU_PRESENCE# is connected to VSS on the processor
package. If pulled-up on the motherboard, CPU_PRESENCE#
may be used to detect the presence or absence of a processor in
the Socket A-style socket.
DBRDY and DBREQ#
Pins DBRDY and DBREQ# are routed to the debug connector.
DBREQ# is tied to V
CC_CORE
with a pullup resistor.
FERR Pin FERR is an output to the system that is asserted for any
unmasked numerical exception independent of the NE bit in
CR0. FERR is a push-pull active High signal that must be
inverted and level shifted to an active Low signal. For more
information about FERR and FERR#, see the “Required
Circuits” chapter of the AMD Athlon™ Processor-Based
Motherboard Design Guide, order# 24363.