DFI EHL9A2 Guide

EHL9A2
COM Express Mini Module
Carrier Board Design Guide
© May 04, 2023 DFI Inc.

2Design Guide | EHL9A2
Copyright
This publication contains information that is protected by copyright. No part of it may be re-
produced in any form or by any means or used to make any transformation/adaptation with-
out the prior written permission from the copyright holders.
This publication is provided for informational purposes only. The manufacturer makes no rep-
resentations or warranties with respect to the contents or use of this manual and specifically
disclaims any express or implied warranties of merchantability or fitness for any particular
purpose. The user will assume the entire risk of the use or the results of the use of this docu-
ment. Further, the manufacturer reserves the right to revise this publication and make changes
to its contents at any time, without obligation to notify any person or entity of such revisions
or changes.
Changes after the publication’s first release will be based on the product’s revision. The web-
site will always provide the most updated information.
© 2023. All Rights Reserved.
Trademarks
Product names or trademarks appearing in this manual are for identification purpose only and
are the properties of the respective owners.
COM Express Specification Reference
PICMG® COM Express® Module Base Specification.
http://www.picmg.org/
FCC and DOC Statement on Class B
This equipment has been tested and found to comply with the limits for a Class B digital
device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reason-
able protection against harmful interference when the equipment is operated in a residential
installation. This equipment generates, uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instruction manual, may cause harmful interference
to radio communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and on, the user is encour-
aged to try to correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and the receiver.
• Connect the equipment into an outlet on a circuit different from that to which the re-
ceiver is connected.
• Consult the dealer or an experienced radio TV technician for help.
Notice:
• The changes or modifications not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
• Shielded interface cables must be used in order to comply with the emission limits.

3Design Guide | EHL9A2
Table of Contents
Chapter 1 - Introduction................................................................................................................6
COM Express Overview..........................................................................................................6
Specification ........................................................................................................................... 7
Block Diagram ........................................................................................................................ 9
Board Layout .......................................................................................................................10
System Memory ..................................................................................................................10
Terminology .........................................................................................................................11
Chapter 2 - Concept....................................................................................................................12
COM Express Module Standards .......................................................................................12
Chapter 3 - Carrier Board Schematic Guidelines......................................................................13
PCI Express Bus ..................................................................................................................13
Serial ATA .............................................................................................................................16
Gigabit Ethernet (GBE).........................................................................................................18
HD Audio...............................................................................................................................23
Universal Serial Bus 2.0 and 3.1 (USB 2.0 and 3.1) ..........................................................27
LVDS ......................................................................................................................................32
Digital Display Interface.......................................................................................................36
Miscellaneous.......................................................................................................................42

4Design Guide | EHL9A2
About this Manual
This manual can be downloaded from the website.
The manual is subject to change and update without notice, and may be based on editions
that do not resemble your actual products. Please visit our website or contact our sales repre-
sentatives for the latest editions.
Warranty
• Warranty does not cover damages or failures that occur from misuse of the product,
inability to use the product, unauthorized replacement or alteration of components
and product specifications.
• The warranty is void if the product has been subjected to physical abuse, improper
installation, modification, accidents or unauthorized repair of the product.
• Unless otherwise instructed in this user’s manual, the user may not, under any cir-
cumstances, attempt to perform service, adjustments or repairs on the product,
whether in or out of warranty. It must be returned to the purchase point, factory or
authorized service agency for all such work.
• We will not be liable for any indirect, special, incidental or consequential damages to
the product that has been modified or altered.
Static Electricity Precautions
It is quite easy to inadvertently damage your PC, system board, components or devices even
before installing them in your system unit. Static electrical discharge can damage computer
components without causing any signs of physical damage. You must take extra care in han-
dling them to ensure against electrostatic build-up.
• To prevent electrostatic build-up, leave the system board in its anti-static bag until
you are ready to install it.
• Wear an antistatic wrist strap.
• Do all preparation work on a static-free surface.
• Hold the device only by its edges. Be careful not to touch any of the components,
contacts or connections.
• Avoid touching the pins or contacts on all modules and connectors. Hold modules or
connectors by their ends.
Safety Measures
• To avoid damage to the system, use the correct AC input voltage range.
• To reduce the risk of electric shock, unplug the power cord before removing the sys-
tem chassis cover for installation or servicing. After installation or servicing, cover
the system chassis before plugging the power cord.
Important:
Electrostatic discharge (ESD) can damage your processor, disk drive and other
components. Perform the upgrade instruction procedures described at an ESD
workstation only. If such a station is not available, you can provide some ESD
protection by wearing an antistatic wrist strap and attaching it to a metal part of
the system chassis. If a wrist strap is unavailable, establish and maintain contact
with the system chassis throughout any procedures requiring ESD protection.

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About the Package
The package contains the following items. If any of these items are missing or damaged,
please contact your dealer or sales representative for assistance.
The accessories in the package may not come similar to the information listed below. This may
differ in accordance with the sales region or models in which it was sold. For more information
about the standard package in your region, please contact your dealer or sales representative.
• Heat Sink (For IHS package CPU)
• Heat Sink (For BARE-DIE CPU)
• Cooler (For IHS packages CPU with wide temperature environment.)
* IHS : Integrated Heat Spreader
Optional Items
The board and accessories in the package may not come similar to the information listed
above. This may differ in accordance with the sales region or models in which it was sold. For
more information about the standard package in your region, please contact your dealer or
sales representative.
Before Using the System Board
Before using the system board, prepare basic system components.
If you are installing the system board in a new system, you will need at least the following
internal components.
• Storage devices such as hard disk drive, etc.
You will also need external system peripherals you intend to use which will normally include
at least a keyboard, a mouse and a video display monitor.

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Chapter 1
INTRODUCTION
Design Guide | EHL9A2
Chapter 1 - Introduction
XCOM Express Overview
This design guide addendum organizes and provides the recommendations of DFI’s COM car-
rier board design for COM-Express Modules. All other Schematic Guidelines for the carrier
board are applicable and can be found in the PICMG Design Guide V1.0. Please contact DFI
sales and application engineers if there are any questions about designing the carrier board,
or you plan to use this processor in applications other than mobile or desktop platforms.
COM Express complies with COM Express standard from the PCI Industrial Computer Manu-
facturers Group (PICMG) which provides next-generation performance of the smallest state
in the art of embedded modules. DFI’s COM Design Support Services (CDSS) help customers
develop and integrate their carrier boards with DFI’s COM modules. CDSS provides a series
of valuable services such as Product, Design Assistance, Software and Thermal Solution ser-
vices, together they help reduce risks when designing carrier boards. For more details, please
visit at “http://www.dfi.com” DFI offers a wide range of COM products to cater to various
customers’ demands. The modular designs add more flexibilities to the system. The COM Ex-
press form factor allows the COM Express Modules to be easily and securely mounted on a
customized solution board. The design and multiple processor choices eliminate CPU integra-
tion worries and allow fast applications supporting for the most dynamic embedded needs.
Mini
Carrier Board
Compact
Basic
COM Express
Carrier Board
COMs are widely used by modular CPU boards with high-integration features.
COM-Express supports a wide range of processors and chipsets. They utilize specialized
technologies, including PCI Express, Serial ATA, USB 2.0, etc. Not only do COMs allow quick
design, they also provide the benefits of easy installation, maintenance and upgrade ease.
Though small in size, COMs implement CPU architectures and basic common circuits.
Many system integrators find that DFI COM solutions have already covered around 80%
of their feature requirements. This makes COM products powerful and cost-efficient.
Carrier board
COM Express Mini Module

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Chapter 1
INTRODUCTION
Design Guide | EHL9A2
XSpecification
SYSTEM Processor Intel Atom®x6000 series and Intel®Celeron®and Pentium®N & J series processors (formerly Code name “Elkhart Lake”)
Memory LPDDR4X max up to 16GB within dual channel and maximum speed depends on SOC.
(The LPDDR4X speed ≤ 3733 MT/s (2RPC/1RPC) and 4267 MT/s (1RPC) which depends on processor.)
Note:
• 8GB/16GB supported by project basis.
• In-band ECC (IBECC) with normal memory chip support on selected ATOM x6000 series SKUs.
IBECC can set enabled or disabled in BIOS setup menu.
BIOS AMI SPI 256Mbit
GRAPHICS Controller Intel®HD Graphics
Feature OpenGL 4.5, DirectX 12, OpenCL 1.2
HW Decode: AVC/H.264, MPEG2, VC1, WMV9, JPEG/MJPEG, HEVC/H.265, VP8, VP9, MVC
HW Encode: AVC/H.264, JPEG/MJPEG, HEVC/H.265, VP9, MVC
Display 1 x DDI
1 x LVDS/eDP
LVDS: single channel 24-bit, resolution up to 1920x1200 @ 60Hz
eDP: resolution up to 4096x2160 @ 60Hz
HDMI: resolution up to 4096x2160 @ 30Hz
DP++: resolution up to 4096x2160 @ 60Hz, 3840x2160 @60Hz
EXPANSION Interface 4 x PCIe x1 (Gen 3)
1 x SD/SDIO (available upon request)
1 x I2C
1 x SMBus
1 x LPC
1 x Speaker
1 x SPI
2 x UART (TX/RX)
AUDIO Interface HD Audio
ETHERNET Controller 1 x Intel®I225IT / I225-LM (10/100/1000Mbps/2.5Gbps)
I/O USB 2 x USB 3.1 Gen2
8 x USB 2.0
SATA 2 x SATA 3.0 (up to 6Gb/s)
eMMC 1 x 8GB/16GB/32GB/64GB*/128GB eMMC 5.1 (available upon request)
DIO 1 x 8-bit DIO

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Chapter 1
INTRODUCTION
Design Guide | EHL9A2
WATCHDOG TIMER Output & Interval System Reset, Programmable via Software from 1 to 255 Seconds
SECURITY TPM dTPM or fTPM (Opational)
Power Type 4.75V~20V, 5VSB, VCC_RTC (ATX mode)
4.75V~20V, VCC_RTC (AT mode)
Consumption TBD
OS SUPPORT OS Support (UEFI
Only) Windows: Windows 10 IoT Enterprise 64-bit
Linux
ENVIRONMENT Temperature Operating: -5 to 65°C, -40 to 85°C
Storage: -40 to 85°C
Humidity Operating: 5 to 90% RH
Storage: 5 to 90% RH
MTBF TBD
MECHANICAL Dimensions COM Express® Mini 84mm (3.3") x 55mm (2.16")
Compliance PICMG COM Express® R3.0, Type 10
STANDARDS AND CER-
TIFICATIONS
Certification CE, FCC

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Chapter 1
INTRODUCTION
Design Guide | EHL9A2
XBlock Diagram

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Chapter 1
INTRODUCTION
Design Guide | EHL9A2
XBoard Layout
TOP VIEW
1
LPDDR4XLPDDR4X
LPDDR4X
SPI
LPDDR4X
COM Express connector
1
EMMC
BOTTOM VIEW
Important:
Boards, and other components. Perform installation procedures at an ESD work-
station only. If such a station is not available, you can provide some ESD protec-
tion by wearing an antistatic wrist strap and attaching it to a metal part of the
system chassis. If a wrist strap is unavailable, establish and maintain contact with
the system chassis throughout any procedures requiring ESD protection.
XSystem Memory
1
LPDDR4XLPDDR4X
LPDDR4X
SPI
LPDDR4X
The system board is equipped with LPDDR4X memory chips onboard.