Jumper
Name
Ref Des
Location
Color
Default
Setting
Description
Core
Oscillator
Power Strap
(GPIO30)
J1H6
Blue
Closed
Open: VCC1P0_STBY (external)
Closed: SFI Out (internal)
Flash Sec
Descriptor
Override Low
(GP33)
J1G4
Blue
Open
Open: Normal
Closed: Security Override
DMI Mode
(GPIO53)
R2G37(PU)
N/A
Pull Up
Pull Up: DC Coupling
Pull Down: AC Coupling
Top Block
Swap
(GPIO55)
R2G46(PU)
N/A
Pull Up
Pull Up: Normal
Pull Down: Swap Top Block (BIOS)
BIOS
Recovery
Strap
(PCH_GP46)
J5A3
Blue
Open
Open: Normal Mode
Closed: BIOS Recovery Mode
A.5
Miscellaneous Jumper Settings
Table 19.
Miscellaneous Jumper/Resistor Settings
Jumper Name
Ref
Des
Locatio
n
Color
Default
Setting
Description
EP JTAG Enable
J6D1
Black
Open
3-pin header for Endpoint JTAG enable/
disable
Shunt 1-2: PCH JTAG only
Shunt 2-3: EP JTAG only
Open: PCH & EP JTAG
GPIO25 DDR3 Voltage
Select
J9C2
Black
Open
Open: VDD1P5_DDR is 1.5V (default)
Closed: VDD1P5_DDR is 1.35V
PCH WDT Enable
J4A1
Black
Open
When closed, this header enables the board
to reset the board when the WDT times out
CPU Fan Override
(CPU_FAN_CTRL)
J7D1
Black
Open
Open: Manual Control Full Speed
Closed: PWM Control
PCH Fan Override
(PWM2_PCHFAN)
J3J2
Black
Shunt [1-2]
Open: PWM Control
Closed: Full Speed
VTT_SA_VID Select
(VTT_SA_CPU_VID0)
J6K2
Black
Shunt [2-3]
Shunt [1-2]: 0.8V
Shunt [2-3]: 0.89V
THRMTRIP Clear
J6E1
Black
Shunt [1-2]
Open: Clear THRMTRIP LED
Closed: Normal
Serial Port Selection
(Port 1)
J3A3
Black
Open
Open: SIO Serial <-> Serial Port #1
Closed: Intel
®
Communications Chipset
89xx Series (Serial Port #2) <-> Serial Port
#1
SIO Enable
(LPC_FRAME_SIO_N)
J3A2
Black
Shunt [1-2]
Open: Disable SIO
Closed: Enable SIO
continued...
Crystal Forest—Technical Reference
Intel
®
Xeon
®
Processor E3-1125C with Intel
®
Communications Chipset 8910 Development Kit
User Guide
October 2012
38
Order No.: 328009-001US