Filter
Top Products
Chapter 11 Pin Descriptions 79
25175H—March 2003 AMD Athlon™ XP Processor Model 8 Data Sheet
Preliminary Information
SADDIN[1:0]# and
SADDOUT[1:0]# Pins
The AMD Athlon XP processor model 8 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,
see the AMD Athlon™ System Bus Specification, order# 21902.
Scan Pins 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# Pin SMI# is an input that causes the processor to enter the system
management mode.
STPCLK# Pin STPCLK# is an input that causes the processor to enter a lower
power mode and issue a Stop Grant special cycle.
SYSCLK and SYSCLK# 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 74 for more
information.
THERMDA and
THERMDC Pins
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 17, “Thermal Diode Electrical Characteristics,” on
page 42 for more information.
VCCA Pin 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.
VID[4:0] Pins 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.
The VID codes and corresponding voltage levels are shown in
Table 28.