AMD 27493, 10, 27488 manual Detailed Pin Descriptions

Preliminary Information

26237C —May 2003 AMD Athlon™ XP Processor Model 10 Data Sheet

11.3Detailed Pin Descriptions

	The information in this section pertains to Table 24 on page 64.
A20M# Pin	A20M# is an input from the system used to simulate address
	wrap-around in the 20-bit 8086.
AMD Pin	AMD Socket A processors do not implement a pin at location
	AH6. All Socket A designs must have a top plate or cover that
	blocks this pin location. When the cover plate blocks this
	location, a non-AMD part (e.g., PGA370) does not fit into the
	socket. However, socket manufacturers are allowed to have a
	contact loaded in the AH6 position. Therefore, motherboard
	socket design should account for the possibility that a contact
	could be loaded in this position.
AMD Athlon™	See the AMD Athlon™ and AMD Duron™ System Bus
System Bus Pins	Specification, order# 21902 for information about the system
	bus pins — PROCRDY, PWROK, RESET#, SADDIN[14:2]#,
	SADDINCLK#, SADDOUT[14:2]#, SADDOUTCLK#,
	SDATA[63:0]#, SDATAINCLK[3:0]#, SDATAINVALID#,
	SDATAOUTCLK[3:0]#, SDATAOUTVALID#, SFILLVALID#.
Analog Pin	Treat this pin as a NC.
APIC Pins, PICCLK,	The Advanced Programmable Interrupt Controller (APIC) is a
PICD[1:0]#	feature that provides a flexible and expandable means of
	delivering interrupts in a system using an AMD processor. The
	pins, PICD[1:0], are the bidirectional message-passing signals
	used for the APIC and are driven to the Southbridge or a
	dedicated I/O APIC. The pin, PICCLK, must be driven with a
	valid clock input.
	Refer to “VCC_2.5V Generation Circuit” found in the section,
	“Motherboard Required Circuits,” of the AMD Athlon™
	Processor Motherboard Design Guide, order# 24363 for the
	required supporting circuitry.
	For more information, see Table 15, “APIC Pin AC and DC
	Characteristics,” on page 40.
CLKFWDRST Pin	CLKFWDRST resets clock-forward circuitry for both the system
	and processor.

Chapter 11 Pin Descriptions 72