AMD 27488 User Manual

26237C—May 2003

The AMD Athlon XP processor model 10 does not support
SADDIN[1:0]# or SADDOUT[1:0]#. SADDIN[1]# is tied to VCC
with pullup resistors, if this bit is not supported by the
Northbridge (future models can support SADDIN[1]#).
SADDOUT[1:0]# are tied to VCC with pullup resistors if these
pins are supported by the Northbridge. For more information,
s e e   t h e   A M D A t h l o n ™   a n d   A M D D u r o n ™   S y s t e m   B u s
Specification, order# 21902.

SCANSHIFTEN, SCANCLK1, SCANINTEVAL, and SCANCLK2
are the scan interface. This interface is AMD internal and is
tied disabled with pulldown resistors to ground on the
motherboard.

SMI# is an input that causes the processor to enter the system
management mode.

STPCLK# is an input that causes the processor to enter a lower
power mode and issue a Stop Grant special cycle.

SYSCLK and SYSCLK# are differential input clock signals
provided to the PLL of the processor from a system-clock
generator.

See “CLKIN, RSTCLK (SYSCLK) Pins” on page 73 for more
information.

Thermal Diode anode and cathode pins are used to monitor the
actual temperature of the processor die, providing more
accurate temperature control to the system.

See Table 13, “Thermal Diode Electrical Characteristics,” on
page 37 for more information.

VCCA is the processor PLL supply. For information about the
VCCA pin, see Table 5, “VCCA AC and DC Characteristics,” on
page 35 and the AMD Athlon™ Processor-Based Motherboard
Design Guide, order# 24363.

To prevent damage to the processor, do not pull this signal High
above 2.5 V. Do not expose this pin to a differential voltage
greater than 1.60 V, relative to the processor core voltage.

The VID[4:0] (Voltage Identification) outputs are used to
dictate the V

CC_CORE

 voltage level.  The VID[4:0] pins are

strapped to ground or left unconnected on the processor
package.  The VID[4:0] pins are pulled up on the motherboard
and used by the V

CC_CORE

 DC/DC converter.