VersaLogic VL-EPM-31 Quick user guide

Hardware
Reference
Manual
DOC. REV. 25 Jan 2017
BayCat
(VL-EPM-31)
Intel®Atom™-based Single
Board Computer with Dual
Ethernet, Video, USB, SATA,
Serial I/O, Digital I/O, Trusted
Platform Module security,
Counter/Timers, Mini PCIe,
mSATA, PCI/104-Plus
Interface, and SPX.

EPM-31 Hardware Reference Manual ii
WWW.VERSALOGIC.COM
12100 SW Tualatin Road
Tualatin, OR 97062-7341
[phone]
Fax [phone]
Copyright © 2016-2017 VersaLogic Corp. All rights reserved.
Notice:
Although every effort has been made to ensure this document is error-free, VersaLogic makes no
representations or warranties with respect to this product and specifically disclaims any implied warranties
of merchantability or fitness for any particular purpose.
VersaLogic reserves the right to revise this product and associated documentation at any time without
obligation to notify anyone of such changes.
PC/104 and the PC/104 logo are trademarks of the PC/104 Consortium.

EPM-31 Hardware Reference Manual iii
Product Release Notes
Release 1.0
January 2016
First production release
Release 1.1
April 2016
Added information regarding I2C support to Table 8, Table 19, and Table 20.
Release 1.2
August 2016
Updated caption for Figure 23, Updated signal information for pins 6 and 14
in table 14.
Release 1.3
October 2016
Added ISA IRQ information.
Release 1.4
January 2017
Updated terminology for updating RTC registers
Technical Support
The EPM-31 support page, at http://www.versalogic.com/private/baycatsupport.asp, contains
additional information and resources for this product including:
Reference Manuals (PDF format)
Operating system information and software drivers
Data sheets and manufacturers’ links for chips used in this product
BIOS information and upgrades
Utility routines and benchmark software
VersaAPI Version 1.2.x
This is a private page for EPM-31 users that can be accessed only be entering this address
directly. It cannot be reached from the VersaLogic homepage.
The VersaTech KnowledgeBase is an invaluable resource for resolving technical issues with
your VersaLogic product.
If you have additional questions, contact VersaLogic Technical Support at [phone].
VersaLogic support engineers are also available via e-mail at [email protected].
REPAIR SERVICE
If your product requires service, you must obtain a Returned Material Authorization (RMA)
number by calling [phone].
Provide the following information:
Your name, the name of your company, your phone number, and e-mail address
The name of a technician or engineer that can be contacted if any questions arise
Quantity of items being returned
The model and serial number (barcode) of each item
A detailed description of the problem
Steps you have taken to resolve or recreate the problem
The return shipping address

EPM-31 Hardware Reference Manual iv
Warranty Repair All parts and labor charges are covered, including return shipping
charges for UPS Ground delivery to United States addresses.
Non-warranty Repair All non-warranty repairs are subject to diagnosis and labor charges,
parts charges and return shipping fees. Specify the shipping method
you prefer and provide a purchase order number for invoicing the
repair.

Note: Mark the RMA number clearly on the outside of the box before returning. Failure to do
so can delay the processing of your return.
RoHS Compliance
The EPM-31 is RoHS-compliant.
ABOUT ROHS
In 2003, the European Union issued Directive 2002/95/EC regarding the Restriction of the use of
certain Hazardous Substances (RoHS) in electrical and electronic equipment.
The RoHS directive requires producers of electrical and electronic equipment to reduce to
acceptable levels the presence of six environmentally sensitive substances: lead, mercury,
cadmium, hexavalent chromium, and the presence of poly-brominated biphenyls (PBB) and poly-
brominated diphenyl ethers (PBDE) flame retardants, in certain electrical and electronic products
sold in the European Union (EU) beginning July 1, 2006.
VersaLogic Corporation is committed to supporting customers with high-quality products and
services meeting the European Union’s RoHS directive.
Cautions
ELECTROSTATIC DISCHARGE
Electrostatic discharge (ESD) can damage boards, disk drives and other components. The circuit
board must only be handled at an ESD workstation. If an approved station is not available, some
measure of protection can be provided by wearing a grounded antistatic wrist strap. Keep all
plastic away from the board, and do not slide the board over any surface.
After removing the board from its protective wrapper, place the board on a grounded, static-free
surface, component side up. Use an antistatic foam pad if available.
The board should also be protected inside a closed metallic anti-static envelope during shipment
or storage.

Note:
The exterior coating on some metallic antistatic bags is sufficiently conductive to cause
excessive battery drain if the bag comes in contact with the bottom-side of the EPM-31.
LITHIUM BATTERY
To prevent shorting, premature failure or damage to the lithium battery, do not place the board on
a conductive surface such as metal, black conductive foam or the outside surface of a metalized
ESD protective pouch. The Lithium battery may explode if mistreated. Do not recharge,
disassemble, or dispose of in fire. Dispose of used batteries promptly.

EPM-31 Hardware Reference Manual v
MOUNTING SUPPORT
The single board computer must be supported at all four mounting points to prevent excessive
flexing when expansion modules are attached and removed. Flex damage caused by excessive
force on an improperly mounted circuit board is not covered under the product warranty. See
page 15 for more details.
EARTH GROUND REQUIREMENT
All mounting standoffs should be connected to earth ground (chassis ground). This provides
proper grounding for EMI purposes. Figure 1 shows the locations of the board’s mounting holes.
All mounting holes identified in Figure 1 must be connected to earth ground.
Figure 1. Attaching the EPM-31 to Earth Ground

EPM-31 Hardware Reference Manual vi
Contents
Introduction .................................................................................................................11
Description........................................................................................................................ 11
Technical Specifications................................................................................................... 13
Thermal Considerations.................................................................................................... 13
EPM-31 Block Diagram ...................................................................................................14
Dimensions and Mounting................................................................................................15
Hardware Assembly.............................................................................................16
Related Documents...........................................................................................................16
Configuration and Setup.............................................................................................17
Initial Configuration .........................................................................................................17
Basic Setup ....................................................................................................................... 17
Jumper Blocks ..................................................................................................................19
Jumpers Blocks in the As-Shipped Configuration...............................................19
Jumper Summary.................................................................................................19
Configuration Switches ....................................................................................................20
Resetting the BIOS to Factory Defaults ..............................................................21
Clearing Non-volatile RAM and RTC Registers.................................................21
BIOS Setup Utility............................................................................................................21
Operating System Installation...........................................................................................22
Board Features............................................................................................................23
CPU...................................................................................................................................23
System RAM.....................................................................................................................23
I/O Interfaces ....................................................................................................................23
Power Delivery.................................................................................................................24
Main Power Connector........................................................................................ 24
Cabling.................................................................................................................25
Power Delivery Considerations...........................................................................25
Power Button.......................................................................................................26
Supported Power States.......................................................................................26
Battery Power Options.........................................................................................27
Cabling.................................................................................................................27
VL-CBR-0203 External Battery Module............................................................. 28
Real Time Clock (RTC)....................................................................................................28
Push-Button Reset ............................................................................................................28
LEDs/Indicators................................................................................................................29
Programmable LED.............................................................................................29
Power LEDs.........................................................................................................30
External Speaker...............................................................................................................30
Mass Storage Interfaces.............................................................................................31
SATA................................................................................................................................31
microSD Socket................................................................................................................32

Contents
EPM-31 Hardware Reference Manual vii
Multi-purpose I/O.........................................................................................................33
USB Interfaces..................................................................................................................33
Cabling.................................................................................................................34
PCIe Mini Card / mSATA................................................................................................34
mSATA Activity LED.........................................................................................36
PCIe Mini Card LEDs .........................................................................................37
User I/O Connector...........................................................................................................38
Cabling.................................................................................................................39
I2C.....................................................................................................................................39
Digital I/O (DIO) ..............................................................................................................40
DIO Guidelines.................................................................................................................41
Voltage.................................................................................................................41
Power States ........................................................................................................42
Cables ..................................................................................................................42
Serial Ports..................................................................................................................43
Serial Port Connectors......................................................................................................43
Serial Port Connector Pinouts .............................................................................44
Cabling.................................................................................................................44
RS-485 Mode Line Driver Control......................................................................44
COM1/COM2 Hardware Configuration........................................................................... 45
Video Interfaces...........................................................................................................46
VGA Interface ..................................................................................................................46
Cabling.................................................................................................................47
Mini Display Port Connector............................................................................................48
Console Redirection ......................................................................................................... 49
Network Interfaces......................................................................................................50
Ethernet Connector..............................................................................................50
Cabling.................................................................................................................51
On-Board Ethernet Status LEDs..........................................................................52
Expansion Interfaces ..................................................................................................53
SPX™Expansion Bus......................................................................................................53
Cabling.................................................................................................................54
VersaLogic SPX Expansion Modules .................................................................54
PC/104-Plus Expansion Bus.............................................................................................55
ISA Bus (on PC/104-Plus and PC/104 Expansion Modules)..............................55
ISA I/O Support...................................................................................................56
ISA Memory Support...........................................................................................56
ISA IRQ Support .................................................................................................57
Each of the IRQs must be enabled in the BIOS Setup utility before they can be
used. (All are disabled by default.)......................................................................57
PCI Bus (on PC/104-Plus and PCI-104 Expansion Modules).............................57
System Resources and Maps.....................................................................................58
CBR-4005B Paddleboard ............................................................................................59
CBR-4005B Paddleboard .................................................................................................59
CBR-4005B Connectors and Indicators ..............................................................59

Contents
EPM-31 Hardware Reference Manual viii
User I/O Connector..............................................................................................60
Cabling.................................................................................................................61
On-board Battery.................................................................................................61
Auxiliary I/O Connector......................................................................................62
Dimensions and Mounting Holes ........................................................................ 63
CBR-2004B Paddleboard ............................................................................................64
CBR-2004B Connectors ...................................................................................................64
Main I/O Connector.............................................................................................65
Cabling.................................................................................................................65
Dimensions and Mounting Holes .....................................................................................66
Thermal Considerations .............................................................................................67
Selecting the Correct Thermal Solution for Your Application ........................................ 67
Heat Plate.............................................................................................................67
System-level Considerations ...............................................................................68
CPU Thermal Trip Points....................................................................................69
Thermal Specifications, Restrictions, and Conditions ........................................70
Overall Restrictions and Conditions....................................................................70
Heat Plate Only Restrictions and Conditions:.....................................................70
Heat Sink Only Considerations: ..........................................................................70
Heat Sink with Fan Considerations:....................................................................70
EPM-31 Thermal Characterization................................................................................... 71
Test Results..........................................................................................................72
Installing the VersaLogic Thermal Solutions...................................................................75
Installing the Passive Heat Sink ..........................................................................75
Installing the Heat Sink Fan ................................................................................76
Figures
Figure 1. Attaching the EPM-31 to Earth Ground.............................................................. v
Figure 2. VL-EPM-31 BayCat Single Board Computer (Top Side)................................. 12
Figure 3. VL-EPM-31 BayCat Single Board Computer (Bottom Side)............................ 13
Figure 4. EPM-31 Block Diagram.................................................................................... 14
Figure 5. EPM-31 Dimensions and Mounting Holes........................................................ 15
Figure 6. Jumper Block Locations.................................................................................... 19
Figure 7. Location of SW1 Configuration Switch Block.................................................. 20
Figure 8. Location and Pin Orientation of the Main Power Connector............................ 24
Figure 9. Location and Pin Orientation of the External Battery Connector...................... 27
Figure 10. VL-CBR-0203 Latching Battery Module........................................................ 28
Figure 11. Locations of the LEDs/Indicators.................................................................... 29
Figure 12. Location of the D11 Dual-color LED.............................................................. 30
Figure 13. Location of the SATA Port.............................................................................. 31
Figure 14. Location of the microSD Socket...................................................................... 32
Figure 15. Location of the USB 3.0 Port (Bottom Side of the Board).............................. 33
Figure 16. Location of the SATA/mSATA Activity LED................................................ 36

Contents
EPM-31 Hardware Reference Manual ix
Figure 17. Location of PCIe Mini Card LEDs.................................................................. 37
Figure 18. Location and Pin Orientation of User I/O Connector...................................... 38
Figure 19. Location and Pin Orientation of Digital I/O Connector .................................. 40
Figure 20. Location and Pin Orientation of Serial Port Connector................................... 43
Figure 21. COM1/COM2 End-point Termination Jumpers.............................................. 45
Figure 22. VGA Connector Location and Pin Configuration........................................... 46
Figure 23. Location of the LVDS Connector.................................................................... 48
Figure 24. Location and Pin Orientation for the J7 Ethernet Connector .......................... 50
Figure 25. Location of Ethernet Status LEDs................................................................... 52
Figure 26. J19 SPX Connector Location and Pin Configuration...................................... 53
Figure 27. CBR-4005B Connectors, Switches, and LEDs................................................ 59
Figure 28. Location and Pin Orientation of the User I/O Connector................................ 60
Figure 29. Location and Pin Orientation of Auxiliary I/O Connector .............................. 62
Figure 30. CBR-4005B Dimensions and Mounting Holes ............................................... 63
Figure 31. CBR-2004B Connectors.................................................................................. 64
Figure 32. J4/J3/J2/J1 Digital I/O Terminal Block Pinouts.............................................. 64
Figure 33. Location and Pin Orientation of the Main I/O Connector............................... 65
Figure 34. CBR-2004B Dimensions and Mounting Holes ............................................... 66
Figure 35. EPM-31EAP CPU Core Temperature Relative to Ambient Temperature ...... 72
Figure 36. EPM-31EBP CPU Core Temperature Relative to Ambient Temperature....... 73
Figure 37. EPM-31ECP CPU Core Temperature Relative to Ambient Temperature....... 74
Figure 38. Installing the Passive Heat Sink ...................................................................... 75
Figure 39. Installing the Heat Sink Fan ............................................................................ 76
Tables
Table 1: Jumper Summary................................................................................................ 19
Table 2: Switch Setting Summary .................................................................................... 20
Table 3: J20 Main Power Connector Pinout..................................................................... 25
Table 4: Supported Power States...................................................................................... 26
Table 5: USB 3.0 J16 Connector Pinout........................................................................... 34
Table 6: PCIe Mini Card / mSATA Pinout....................................................................... 34
Table 7: PCIe Mini Card LED States................................................................................ 37
Table 8: J4 I/O Connector Pinout and Pin Orientation..................................................... 39
Table 9: J21 I/O Connector Pinout ................................................................................... 41
Table 10: J13 COM1/COM2 Connector Pinout ............................................................... 44
Table 11: COM3/COM4 Termination Jumpers................................................................ 45
Table 12: J5 VGA Video Output Pinout........................................................................... 47
Table 13: J3 Mini DisplayPort Connector Pinout............................................................. 49
Table 14: Ethernet Connector Pinout................................................................................ 51
Table 15: Ethernet Status LEDs........................................................................................ 52
Table 16: SPX Connector Pinout...................................................................................... 54
Table 17: PCI/104-Plus Connector (PCI) Maximum Current.......................................... 55

Contents
EPM-31 Hardware Reference Manual x
Table 18: Available ISA Bus I/O Ranges ......................................................................... 56
Table 19: User I/O Connector Pinout ............................................................................... 60
Table 20: Auxiliary I/O Connector Pinout........................................................................ 62
Table 21: Main I/O Connector Pinout............................................................................... 65
Table 22: CPU Thermal Trip Points................................................................................. 69
Table 23: Temperature Monitoring Programs .................................................................. 69
Table 24: Absolute Minimum and Maximum Air Temperatures..................................... 70
Table 25: EPM-31 Thermal Testing Setup....................................................................... 71

EPM-31 Hardware Reference Manual 11
Introduction
Description
The EPM-31 BayCat is a feature-packed single board computer (SBC) designed to support OEM
applications where high reliability and long-term availability are required. Its features include:
Intel†Atom†“Bay Trail” processor,
quad, dual, or single core with
processor clock rates up to 1.91 GHz
(Atom E3845)
Integrated IntelGen7 graphics core,
supports DirectX11, Open GL3, and
H.264, MPEG-2 encoding/decoding
Analog and Mini DisplayPort video
outputs
Up to 8 GB DDR3L memory, one
SO-DIMM socket
Two Intel I210-IT-based Ethernet
ports, auto-detect 10Base-T /
100Base-TX / 1000Base-T
One USB 3.0 port and four USB 2.0
ports
Trusted Platform Module
Two RS-232/422/485 serial ports
Three 8254 timer/counters
24 digital I/O lines (16 on the
EPM-31 board and an additional eight
when using the VL-CBR-4005
paddleboard)
SATA port, 3 Gb/s
Mini PCIe / mSATA socket, supports
Wi-Fi modems, GPS receivers, flash
storage, and other modules
SPX expansion
PC/104 form factor with PC/104-Plus
expansion
Customization available
The EPM-31 is compatible with popular operating systems such as Microsoft†Windows†,
Windows Embedded, Linux, VxWorks†, and QNX†.
EPM-31 boards are subjected to complete functional testing and are backed by a limited five-year
warranty. Careful parts sourcing and US-based technical support ensure the highest possible
quality, reliability, service, and product longevity for this exceptional single-board computer
(SBC).
Figure 2 shows the connectors and major components on the top side of the board. Figure 3
shows the connectors and major components on the bottom side of the board.
1

Introduction
EPM-31 Hardware Reference Manual 12
Item/
[Reference
Designator]
Description
Item/
[Reference
Designator]
Description
A
Intel Atom “Bay Trail” SoC
J [J14]
PCIe Minicard/mSATA connector
B [J7]
Ethernet port 0/1 connector
K
FPGA device
C [J21]
Digital I/O connector
L [J20]
Main power connector
D [J13]
COM1/COM2 Serial port connector
M [J5]
VGA connector
E [J19]
SPX connector
N [J17]
microSD card socket
F [V1]
Configuration jumpers
O [J24]
Fan connector
G [J4]
User I/O (CBR-4005B mating connector)
P [J3]
Mini DisplayPort connector
H [J8]
External battery connector
Q [J2]
SATA connector
I [SW1]
Configuration switches
Figure 2. VL-EPM-31 BayCat Single Board Computer (Top Side)

Introduction
EPM-31 Hardware Reference Manual 13
Item/
[Reference
Designator]
Description
A [J11]
PC/104 Legacy PCI expansion connector
B
Trusted Platform Module (TPM) device
C [J16]
USB 3.0 port
D [J9]
SODIMM socket
E [J10A/J10B]
PC/104 Legacy ISA expansion connector
F
Ethernet transformers
Figure 3. VL-EPM-31 BayCat Single Board Computer (Bottom Side)
Technical Specifications
See the BayCat Data Sheet for complete specifications.
Thermal Considerations
The operating temperature for the EPM-31 is -40 °C to +85 °C, de-rated -1.1 °C per 305m (1,000
ft.) above 2,300m (7,500 ft.). All BayCat models include a rigid-mount heat plate thermal
solution. Refer to the Chapter 13, beginning on page 67 for information on additional thermal
solutions.

Introduction
EPM-31 Hardware Reference Manual 14
EPM-31 Block Diagram
Figure 4. EPM-31 Block Diagram

Introduction
EPM-31 Hardware Reference Manual 15
Dimensions and Mounting
The EPM-31 complies with the PC/104 standard which provides for specific mounting hole and
PC/104-Plus stack locations as shown in Figure 5.
Figure 5. EPM-31 Dimensions and Mounting Holes
(Not to scale. All dimensions in inches.)
CAUTION:
The EPM-31 must be supported at all four mounting points to prevent
excessive flexing when expansion modules are attached and removed. Flex
damage caused by excessive force on an improperly mounted circuit board is
not covered under the product warranty.

Introduction
EPM-31 Hardware Reference Manual 16
HARDWARE ASSEMBLY
The EPM-31 mounts on four hardware standoffs using the corner mounting holes. These
standoffs are secured to the underside of the circuit board using pan head screws.
The entire assembly can sit on a table top or be secured to a base plate. When bolting the unit
down, make sure to secure all standoffs to the mounting surface to prevent circuit board flexing.
An extractor tool is available (part number VL-HDW-201) to separate the PC/104 modules from
the stack.
Related Documents
The following documents available are on the EPM-31 Product Support Web Page:
EPM-31 Programmer’s Reference Manual –provides information on the board’s resources
(memory, I/O, and IRQs), a description of the FPGA’s registers, and programming
information for the board’s hardware interfaces.
EPM-31 BIOS Reference Manual –provides information on accessing and configuring
settings in the BIOS Setup utility. All BIOS menus, submenus, and configuration options are
described.
VersaAPI Installation and Reference Guide –describes the shared library of API calls for
reading and controlling on-board devices on certain VersaLogic products.
Additional documents:
Processor
Intel Atom E38xx (formerly
“Bay Trail”) System-on-Chip
(SoC) Processor
Intel Atom Processor E3800 Product Family Datasheet
Ethernet Controller
Intel I210-IT Gigabit Ethernet
Controller
Intel I210-IT Datasheet
PC/104 Specification
http://www.versalogic.com/products/PC104/index.asp
PC/104-Plus Specification
http://www.versalogic.com/products/PC104/index.asp

EPM-31 Hardware Reference Manual 17
Configuration and Setup
Initial Configuration
The following components are recommended for a typical development system.
VL-EPM-31 single board computer
VL-MM9-xxEBN DDR3 SO-DIMM module (see System RAM)
ATX power supply with motherboard and disk drive connectors
VGA video monitor
USB Keyboard
USB Mouse
SATA hard drive
The following VersaLogic cables and accessories are recommended.
VGA Video adapter cable (CBR-1204)
User I/O cable (CBR-4005) and accompanying paddleboard (CBR-4005B)
Power adapter cable (CBR-1008)
VL-CBR-0702 –SATA data cable
VL-CBR-0401 –ATX to SATA power adapter
VL-CBR-1604 –12-inch dual Ethernet RJ-45 adapter
You will also need a Windows (or other OS) installation CD/DVD and corresponding drive.
Basic Setup
The following steps outline the procedure for setting up a typical development system. The
EPM-31 should be handled at an ESD workstation or while wearing a grounded antistatic wrist
strap.
Before you begin, unpack the EPM-31 and accessories. Verify that you received all the items you
ordered. Inspect the system visually for any damage that may have occurred in shipping. Contact
[email protected] immediately if any items are damaged or missing.
Gather all the peripheral devices you plan to attach to the BayCat as well as their interface and
power cables.
It is recommended that you attach standoffs to the board (see Hardware Assembly) to stabilize the
board and make it easier to work with.
2

Configuration and Setup
EPM-31 Hardware Reference Manual 18
1. Install Memory
Insert the DDR3L DRAM module into the SO-DIMM socket on the bottom side of the
board and latch it into place.
2. Attach Cables and Peripherals

Note:
The instructions below refer to connector locations by the reference designators
printed on the board’s silkscreen. Figure 2 (page 12) and Figure 3 (page 13) show the
locations of all the connectors along with their reference designators.
Plug the VGA cable VL-CBR-1204 into socket J5. Attach the cable to a VGA display.
(Alternatively, you can attach a DisplayPort-enabled display to the Mini DisplayPort
connectors at J3. The VL-EPH-V6 video adapter card converts DisplayPort output to
LVDS.)
Plug the VL-CBR-4005B paddleboard into socket J4.
Plug a USB CD-ROM drive, USB keyboard, and USB mouse into any of the USB
connectors of the CBR-4005B paddleboard.
Plug the SATA data cable VL-CBR-0702 into socket J2. Attach a hard drive to the
connector on the cable.
Attach the SATA power adapter cable VL-CBR-0401 to the ATX power supply and
SATA drive.
Optionally, attach a LAN cable to either of the Ethernet connectors at J7 on the EPM-31
using the VL-CBR-1604 RJ-45 adapter.
3. Attach Power
Plug the power adapter cable VL-CBR-1008 into socket J20. Attach the motherboard
connector of the ATX power supply to the adapter.
4. Review Configuration
Before you power up the system, double-check all the connections. Make sure all cables
are oriented correctly and that adequate power will be supplied to the VL-EPM-31 and
peripheral devices.
5. Power On
Turn on the ATX power supply and the video monitor. If the system is correctly
configured, a video signal should be present.
6. Select a Boot Drive
During startup, press <CTRL> <B> to display the boot menu. Insert the OS installation
CD in the CD-ROM drive and select to boot from the CD-ROM drive.
7. Install Operating System
Install the operating system according to the instructions provided by the operating
system manufacturer. (See Operating System Installation on page 22.)

Configuration and Setup
EPM-31 Hardware Reference Manual 19
Jumper Blocks
JUMPERS BLOCKS IN THE AS-SHIPPED CONFIGURATION
Figure 6. Jumper Block Locations
JUMPER SUMMARY
Table 1: Jumper Summary
Jumper Block
Description
Reference
V1 [1-2]
COM1 Rx End-point termination
In –COM1 terminator enabled for RS-485/RS-422
Out –COM1 terminator disabled (default)
Table 11, page 45
V1 [3-4]
COM4 Rx End-point termination
In –COM2 terminator enabled for RS-485/RS-422
Out –COM2 terminator disabled (default)
Table 11, page 45

Configuration and Setup
EPM-31 Hardware Reference Manual 20
Configuration Switches
Figure 7 shows the as-shipped switch configuration with all switches in the Off position. The Off
position is toward the center of the board.
Figure 7. Location of SW1 Configuration Switch Block
Table 2: Switch Setting Summary
SW1 Switch
Position
Description
Position 1
Clears non-volatile RAM and clears resets real-time clock registers (see page 21)
Off –Normal operation (default)
On –Clears battery backed up non-volatile memory bytes 0xE-0x7F and clears battery
backed-up RTC registers
Position 2
No Battery Switch (see Integrator’s Note below)
Off –A battery is being used (default)
On –A battery is not being used
Position 3
Reset BIOS to factory defaults (see page 21)
Off –Normal operation (default)
On –Resets BIOS to factory defaults when the board boots.
Position 4
For factory use only. Always leave in the Off position.
Position 5
SPI Flash Security –Not supported. Leave in the Off position.
Position 6
BIOS select
Off –Primary BIOS (default)
On –Backup BIOS