R

Figure 74. Termination Plane

TDP

N/C

TDN

RDP

RDN

Intel® 820E Chipset

RJ-45

Magnetics Module

Termination Plane

Additional capacitance that may need to be added for EFT testing

term_plane

2.22.5.Intel® 82562ET/EM Disable Guidelines

To disable the Intel 82562ET/EM, the device must be isolated (disabled) prior to reset (RSM_PWROK) asserting. Using a GPIO, such as GPO28 to be LAN_Enable (enabled high), LAN will default to enabled on initial power-up and after an AC power loss. This circuit shown below will allow this behavior. BIOS by controlling the GPIO can disable the LAN microcontroller.

Figure 75. Intel® 82562ET/EM Disable Circuit

VCC3_SBY

RSM_PWROK

10 k

GPIO_LAN_ENABLE

10 k

LAN Disable Circuit

MMBT3906

Intel® 82562ET/EM_Disable

Design Guide

119

Page 119
Image 119
Intel 820E manual Intel 82562ET/EM Disable Guidelines, LAN Disable Circuit