
Intel® Server Board SE7520AF2 TPS
Functional Architecture
Revision 1.2
39
Intel order number C77866-003
ICH5-R Signal
Type
Pin
PWR Well
Tolerance
Description
GPO18/STP_PCI# Output
U21
Core 3.3V TP
GPO19/SLP_S1# Output
T20
Core
3.3V
TP
GPO20/STP_CPU# Output
U22 Core
3.3V
Video
Disable
GPO21/C3_STAT# Output
R1 Core
3.3V
SCSI
Disable
GPO22/CPUPERF# Output
U20
Core 3.3V TP
GPO23/SSMUXSEL# Output F22 Core
3.3V
OEM RMC Connector
POST complete Indicator
GPIO24/CLKRUN#
I/O
AC1
Resume
3.3V
Board ID 1
GPIO25
I/O
W3
Resume
3.3V
Board ID 2
GPIO27 I/O
V3
Resume
3.3V
Source Clock Enable 0
(HP PCI-E)
GPIO28 I/O
W2
Resume
3.3V
Source Clock Enable 1
(HP PCI-E)
GPIO32 I/O
T1
Core
3.3V
TP
GPIO34
I/O
F21
Core
3.3V
IDE Primary Cable Sense
GPI40/REQ4# Input
C6
Core 3.3V CMOS
Clear
GPI41/LDRQ1# Input
R2
Core
3.3V
Emergency Bank Select
GPO48/GNT4#
Output
A4
Core
3.3V
FRB Timer Halt
3.1.4.10 System Management Bus (SMBus 2.0)
The ICH5-R contains an SMBus host interface that allows the processor to communicate with
SMBus slaves. This interface is compatible with most I
2
C devices and special I
2
C commands
are implemented. The SMBus host controller for the ICH5-R provides a mechanism for the
processor to initiate communications with SMBus peripherals (slaves).
The ICH5-R supports slave functionality, including the Host Notify protocol. Hence, the host
controller supports eight command protocols of the SMBus interface: Quick Command, Send
Byte, Receive Byte, Write Byte/Word, Read Byte/Word, Process Call, Block Read/Write, and
Host Notify. See the System Management Bus (SMBus) Specification, Version 2.0.
3.2 Processor
Sub-system
The Intel® Server Board SE7520AF2 supports either one or two Intel® Xeon™ processors with
1MB L2 cache or Intel® Xeon™ processors with 2MB L2 cache with frequencies starting at 2.8
GHz using 90 nanometer technology and utilizing an 800MHz front side bus. Previous
generations of the Intel Xeon processor are not supported. When two processors are installed,
both must be of identical revision, core voltage, cache size, and bus/core speed. When only one
processor is installed, it must be populated into the socket labeled “CPU_1” with the other CPU
socket remains unpopulated. The support circuitry for the processor sub-system consists of the
following:
Dual 604-pin zero insertion force (ZIF) processor sockets
Processor host bus AGTL+ support circuitry