IEI Integration ICE-DB-9S - Manual (Page 87)

ICE Module
Page 74
4.11.4.2 LAN Ground Plane Separation
Isolated separation between the analog ground plane and digital ground plane is
recommended. If this is not implemented properly then bad ground plane partitioning
could cause serious EMI emissions and degrade analog performance due to bouncing
noise. The plane area underneath the magnetic module should be left void. The void
area is to keep transformer induced noise away from the power and system ground
planes. The isolated ground, also called chassis ground, connects directly to the fully
shielded RJ-45 connector. For better isolation it is also important to maintain a gap
between chassis ground and system ground that is wider than 60mils. For ESD
protection a 3kV high voltage capability capacitor is recommended to connect to this
chassis ground for ESD protection. Additionally, a ferrite bead can be placed parallel
to the capacitor.
4.12 LPC (Low Pin Count Interface)
The Low Pin Count Interface was defined by the Intel Corporation to facilitate the
industries transition toward legacy free systems. It allows the integration of
low-bandwidth legacy I/O components within the system, which are typically provided
by a Super I/O controller. Furthermore, it can be used to interface Firmware Hubs,
Trusted Platform Module (TPM) devices and Embedded Controller solutions. Data
transfer on the LPC bus is implemented over a 4 bit serialized data interface, which
uses a 33MHz LPC bus clock. For more information about LPC bus refer to the 'Intel
Low Pin Count Interface Specification Revision 1.1'.
4.12.1 Signal Description
Since COM Express is designed to be a legacy free standard for embedded modules,
it does not support legacy functionality such as PS/2 keyboard/mouse, serial and
parallel ports. Instead it provides an LPC interface that can be used to add peripheral
devices to the carrier board design. The reduced pin count of the LPC interface makes
it easy to implement such devices. All corresponding signals can be found on the
modules connector rows A and B.