Texas Instruments AM438x ePOS EVM User manual

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AM438x ePOS EVM Hardware
User's Guide
SPRUIF8–June 2017
AM438x ePOS EVM Hardware
This document describes the hardware architecture of the AM438x evaluation module (EVM), part number
TMDXEVM438x, which is based on the Texas Instruments AM438x processor. This EVM is also
commonly known as the AM438x Electronic Point of Sale (ePOS) EVM.
Contents
1 Description.................................................................................................................... 3
2 System View.................................................................................................................. 3
3 Functional Blocks Description.............................................................................................. 5
3.1 Processor ............................................................................................................ 5
3.2 Clocks ................................................................................................................ 6
3.3 Reset Signals........................................................................................................ 6
3.4 Memories Supported ............................................................................................... 6
3.5 SDMMC0............................................................................................................. 6
3.6 10/100 Ethernet..................................................................................................... 6
3.7 USB................................................................................................................... 7
3.8 Connectivity.......................................................................................................... 7
3.9 UART................................................................................................................. 7
3.10 ADC................................................................................................................... 7
3.11 Smart Card .......................................................................................................... 7
3.12 Camera............................................................................................................... 7
3.13 Audio ................................................................................................................. 7
3.14 Printer Header....................................................................................................... 7
3.15 Magnetic Stripe Reader............................................................................................ 8
4 Power Supplies .............................................................................................................. 8
4.1 Power Source ....................................................................................................... 8
4.2 Power Sequencing.................................................................................................. 8
4.3 Power-Management IC Power Supplies......................................................................... 8
4.4 APM Sense Resistors.............................................................................................. 9
5 Configuration and Setup.................................................................................................... 9
5.1 Boot Configuration.................................................................................................. 9
5.2 I2C Address Assignments........................................................................................ 10
5.3 I2C ID Memory..................................................................................................... 10
5.4 JTAG................................................................................................................ 10
6 User Interfaces ............................................................................................................. 11
6.1 Keypad.............................................................................................................. 11
6.2 LEDs ................................................................................................................ 11
6.3 Audio Buzzer....................................................................................................... 11
6.4 Display.............................................................................................................. 11
7 Pin Use Description........................................................................................................ 11
7.1 Functional Interface Mapping.................................................................................... 11
8 Board Connectors.......................................................................................................... 12
8.1 SDMMC0 – J10.................................................................................................... 12
8.2 LCD Connector – J44............................................................................................. 12
8.3 Touch Connector – J45........................................................................................... 14
8.4 Ethernet – J8....................................................................................................... 14
8.5 USB ................................................................................................................ 14
8.6 Camera Interface Header – J15................................................................................. 15

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8.7 HDMI Header Connector – J32.................................................................................. 16
8.8 RS-232 Connectors............................................................................................... 16
8.9 Smart Card Connector – J27 .................................................................................... 17
8.10 SAM Card Connector – J28, J29, and J58 .................................................................... 17
8.11 Tamper Header – J34 ............................................................................................ 18
8.12 Platform Test Header – J35...................................................................................... 19
8.13 Magnetic Stripe Reader Header – J36 ......................................................................... 20
8.14 ADC Input Header – J37 ......................................................................................... 20
8.15 GPIO Header – J38............................................................................................... 21
8.16 Printer Header – J90.............................................................................................. 22
8.17 SPI Headers ....................................................................................................... 23
8.18 I2C Header – J39 ................................................................................................. 23
8.19 Automation Header – J97........................................................................................ 24
9 EVM Important Notices.................................................................................................... 24
List of Figures
1 AM438x ePOS EVM Top View............................................................................................. 3
2 AM438x ePOS EVM Bottom View......................................................................................... 4
3 AM438x ePOS EVM Block Diagram ...................................................................................... 5
List of Tables
1 AM438x Power Supplies From TPS65218............................................................................... 8
2 Other Power Supplies....................................................................................................... 8
3 AM438x ePOS EVM APM Sense Resistors ............................................................................. 9
4 SYSBOOT DIP Switches ................................................................................................... 9
5 AM438x ePOS EVM EEPROM Data .................................................................................... 10
6 AM438x SDMMC0 Connector Pin Details .............................................................................. 12
7 AM438x LCD Connector Pin Details..................................................................................... 12
8 LCD Capacitive Touchscreen Pin Details............................................................................... 14
9 AM438x 10/100 Ethernet Pin Details.................................................................................... 14
10 AM438x Micro AB Connector – USB Port 0 Pin Details .............................................................. 14
11 AM438x Type A Connector – USB Port 1 Pin Details................................................................. 15
12 Camera Interface Header Pin Details ................................................................................... 15
13 HDMI Header Pin Details ................................................................................................. 16
14 RS-232 Connector 1 Pin Details ......................................................................................... 16
15 RS-232 Connector 2 Pin Details ......................................................................................... 17
16 Smart Card Connector Pin Details....................................................................................... 17
17 SAM Card Connector Pin Details ........................................................................................ 17
18 Tamper Header Pin Details............................................................................................... 18
19 Platform Test Header Pin Details ........................................................................................ 19
20 Magnetic Stripe Reader Header Pin Details............................................................................ 20
21 ADC Input Header Pin Details............................................................................................ 20
22 GPIO Header Pin Details.................................................................................................. 21
23 Printer Header Pin Details ................................................................................................ 22
24 SPI - Header 1 Pin Details................................................................................................ 23
25 SPI - Header 2 Pin Details................................................................................................ 23
26 I2C - Header Pin Details .................................................................................................. 23
27 Automation - Header Pin Details......................................................................................... 24

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AM438x ePOS EVM Hardware
SmartReflex is a trademark of Texas Instruments.
Micron is a registered trademark of Micron.
Samtec is a registered trademark of Samtech Inc.
1 Description
The AM438x ePOS EVM is a stand-alone test, development, and evaluation module system that lets
developers write software and develop hardware around an AM438x processor subsystem. The main
elements of the AM438x subsystem are already available on the base board of the EVM. The base board
gives developers the basic resources needed for most general-purpose type projects that encompass the
AM438x as the main processor. Furthermore, additional, common peripherals, such as memory, sensors,
LCD, Ethernet physical layer (PHY), and so on, are built into the EVM so that prospective systems can be
modeled quickly without significant additional hardware resources.
The following sections give more details regarding the EVM.
2 System View
Figure 1 and Figure 2 show the system view of the AM438x ePOS EVM.
Figure 1. AM438x ePOS EVM Top View

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Figure 2. AM438x ePOS EVM Bottom View

SMART CARD
CONN
12X2 HDR
NAND
4GBIT
LPDDR2
8GBIT
SMART
CARD PHY
PMIC &
REGULATORS
HDMI DRVR
32 BIT
BUFFER (x2)
TWL1200
RS232 PHY
ETH PHY
AUDIO
CODEC
SPI FLASH
512MBIT
MAG STRIPE HDR
JTAG 10X2
HDR
DSS
SC, I2C
UART 0
UART 1
UART3,MMC1,
McASP0
I2C0
GPIO
McASP1
USB
DEBUG
RMII
SAM CARD
CONNX3
MICRO AB
GPIO 2X16
KEYS
TAMPER BOARD
CAMERA BOARD
7" LCD WITH CAPACITIVE TOUCH
BATTERY BOARD
8x2 HDR
USB TYPE- A
MICRO AB
COM8
CONN
J
T
A
G
U
S
B
1
U
S
B
0
C
A
M
1
Q
S
P
I
M
M
C
0
D
D
R
G
P
M
C
RS232 PHY
AM438X
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3 Functional Blocks Description
The AM438x ePOS EVM has a camera board and/or wireless add-on boards. Figure 3 shows the block
diagram of the ePOS EVM.
Figure 3. AM438x ePOS EVM Block Diagram
The following sections describe the major blocks of the ePOS EVM.
3.1 Processor
The AM438x processor is the central processor to this EVM. All the resources onboard surround the
AM438x processor to provide development capabilities for hardware and software. See the AM438x data
sheet and TRM for details about the processor.
System configuration signals (SYSBOOT0 to SYSBOOT18) on the EVM can be set using resistors and
switches to define some start-up parameters on the AM438x processor. See Section 5 for more details.

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3.2 Clocks
Several clocks in the EVM support the AM438x processor. The main clock for the processor is derived
from a 25-MHz crystal. An onboard oscillator in the AM438x device generates the base clock and
subsequent module clocks as needed within the AM438x processor. A 32-kHz clock for the real-time clock
(RTC) on the AM438x device is derived from a 32.768-kHz crystal on the board.
The EVM also supports an option to connect an external clock using a subminiature version A (SMA)
connector for both these clocks. However, hardware modifications are needed to isolate the onboard
crystals and connect the external clock. See the schematics and TRM for details.
3.3 Reset Signals
Power-on reset to the processor is driven from the power good signal of the power manager and by a hard
reset switch. Asserting this switch also activates the reset signal SYS_RESETn, which runs to several
peripherals and the AM438x and resets those peripherals.
3.4 Memories Supported
3.4.1 LPDDR2 SDRAM
The AM438x ePOS EVM contains 8Gb (256M x 32, 2 dies) of LPDDR2 SDRAM memory from Micron®,
which has dual dies. The part number for the LPDDR2 SDRAM memory device used is
MT42L256M32D2LG-25. The package used is an 168-ball VFBGA package.
3.4.2 NAND Flash
The ePOS EVM has a NAND type of flash. The part number of the memory device used is
MT29F4G08AB, which is a 4Gb (512M × 8) of flash memory. The GPMC signals are used to
communicate with this memory.
3.4.3 QSPI Flash
A QSPI flash of 512Mb, part number MX66L51235FMI-10G, is used in this design. The QSPI flash boot is
enabled through this flash. This flash is connected to the SPI0 port of the processor.
3.4.4 Board Identity Memory
Each board contains a serial EEPROM that contains board-specific data that lets the processor
automatically detect which board is connected and the version of that board. Other hardware-specific data
can be stored on this memory device as well. The part number of the memory device is CAT24C256WI-G.
See Section 5 for details on the data in this memory.
3.5 SDMMC0
The SDMMC0 connector on the ePOS EVM is a microSD card socket, part number MHC-W21-601. This
device is a standard SD/MMC card type of connector. The SDMMC0 connector is connected to the MMC0
port of the AM438x processor. Check the AM438x data sheet and TRM for supported card types and
densities.
3.6 10/100 Ethernet
The AM438x ePOS EVM uses the 10/100 Ethernet transceiver (DP83848J) from TI, which is connected to
the J8 RJ45 connector.
The reset on the transceiver is driven by the board system reset signal, SYS_RESETn, and the individual
reset signal, ETHER_RESETn, that is controlled by the GPIO of the AM438x processor. A 50-MHz crystal
oscillator drives the clock signal for the DP83848J device.
The PHY address is set to 0x10h.

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3.7 USB
The AM438x ePOS EVM supports two USB ports. The USB ports are connected to a microAB connector
and a standard type-A connector. The ESD device, TPD4S012, and common choke filter, ACM2012
(TDK), are used on the USB signals before they are connected to the AM438x pins. The ID pin of the
microAB connector can be tied to ground through a J24 jumper to look like a B device.
3.8 Connectivity
The AM438x ePOS EVM supports MCS COM8 form factor wireless boards from TI through the J21 COM
connector, which is a Samtec®card edge-type connector, part number MEC6-150-02-S-D-RA1. This
connector supports COM8 boards; more details are in the MCS COM8 board documents.
The COM connector requires 3.6 V, 442 mA on the power supply. Therefore a TPS79501 LDO regulator is
used to provide this voltage supply from the base 5.0-V supply.
The signals on the COM board are all 1.8-V voltage level. Therefore voltage translators are placed to
convert to and from 3.3 V of the AM438x rail for a particular signal that is running at 3.3 V.
3.9 UART
This EVM supports two UART ports, UART0 and UART1. The UART0 port from the processor is
converted to USB using the FT2232HL USB-to-UART bridge. UART1 is terminated on a DB9 connector
using the MAX3243 RS-232 transceiver between the AM438x and the DB9 connector. UART0 can also be
optionally terminated with a DB9 connector and a RS-232 transceiver. The RS-232 and DB9 connectors
are unpopulated on the board.
3.10 ADC
The analog inputs to the AM438x device are terminated on the J36 connector, where a magnetic-stripe
assembly must be connected.
3.11 Smart Card
There is a full smart card connector FCI, part number 52400-25ALF, on the EVM. There are also three
SAM card sockets onboard. A TCA5013 Smartcard PHY controls these cards and is controlled by I2C2
from the AM438x.
The PHY I2C address is set to 0x3E.
3.12 Camera
Camera interface from the AM438x processor is terminated on the 12x2 header J15. The custom-made
camera module from TI shall be interfaced with this header. This camera module is on a separate camera
board that attaches at a right angle, so that the camera can face horizontally when the ePOS EVM is
laying on a testbench.
The I2C address set to camera module is 0x30.
3.13 Audio
This EVM uses an audio codec from TI, part number TLV320AIC3111, for the audio input and output. This
audio codec is connected through the McASP1 and I2C interfaces to the AM438x. The microphone is
implemented as a 3.5-mm jack with stereo connection. Speaker out is implemented with integrated
speakers. The PUI speakers are attached to the PCB and their solder lugs are connected to the
throughhole connections for each speaker. The audio codec reset is driven by the board system reset,
SYS_RESETn, and an individual reset signal that is controlled by a GPIO of the AM438x.
3.14 Printer Header
This EVM has a 2 × 12 header to connect to an external printer. The header connects several GPIOs, SPI
buses, and PWM signals to control a printer.

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3.15 Magnetic Stripe Reader
This EVM provides a 7-pin connector, part number 0533980771, to connect to the magnetic stripe reader.
The magnetic stripe reader is connected to the ADC analog inputs 0 to 7 of the AM438x processor.
4 Power Supplies
This section describes how the power supplies required for the design are generated.
4.1 Power Source
The AM438x ePOS EVM uses an external AC to +5 VDC (rated 2.5 A minimum) power adapter. The
switch near the power cable is used for powering on and off. The main power is on when the power switch
is positioned away from the power supply jack. The main power is off when the power switch is positioned
closest to the power supply jack.
4.2 Power Sequencing
The power sequencing requirements of the AM438X processor (see the AM438x data sheet) are
automatically handled by the TPS65218 PMIC.
4.3 Power-Management IC Power Supplies
The AM438x ePOS EVM uses the TPS65218 power-management IC from TI. The I2C0 on the AM438x is
used to control the SmartReflex™ port and control port on the TPS65218 device. For the AM438x
processor, the following power supplies from the TPS65218 device are used (see Table 1).
Table 1. AM438x Power Supplies From TPS65218
TPS65218 Power Supply AM438x Power Rail Voltage (V)
VDCDC1 VDD_CORE 1.1 V
VDCDC2 VDD_MPU 1.1 V
VDCDC3 VDD2, VDDCA, VDDQ of LPDDR2 1.2 V
VLS1 VDD_DDR 1.2 V
V1_8D VDDS_CLKOUT, VDDS_OSC, VDDS_SRAM_CORE_BG,
VDDS_SRAM_MPU_BB VDDS_PLL_DDR, VDDS_PLL_MPU,
VDDA1P8V_USB0, VDDA1P8V_USB1, VPP, VDDA_MC_ADC, VDDA_TS_ADC,
VDDS_CTM, VDDS, VDDS_RTC, COM8, Tamper, and ADC input sections 1.8 V
V1_0BAT VDD_TPM 1.0 V
V1_8BAT VDDS_TPM 1.8 V
V3_3D_AM438X from
TPS63031 VDDSHV 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 3.3 V
V5_0D HDMI circuitry, USB0 power 5.0 V
Table 2. Other Power Supplies
Power Supply Power Rail Voltage (V)
V1_8LPDDR2 from
TPS78101 VDD1 of LPDDR2 1.8 V
V3_3D NAND memory, QPSI flash, Ethernet PHY, SDMMC0, board ID memory, ARM
JTAG, buffers of FTDI section, LCD buffer, touchscreen, camera module, HDMI
buffer, audio codec, RS-232 sections, COM8 sections, smart card sections,
tamper header, platform test section, GPIO header, and printer 3.3 V
V3_3FTDI FT2232 section from TPS79333 3.3 V
VBAT LCD POWER generation, camera module, VCOM_BAT generation for COM8 module, USB1 power generation, platform test section, LEDs, GPIO header,
buzzer, printer xx V
V1_2D HDMI section power 1.2 V

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4.4 APM Sense Resistors
The AM438x ePOS EVM has the following subsystems with current sense resistors (see Table 3). These
resistors allow measurement of power on each power rail, to check AM438x power requirements during
real-time software execution. The value of the resistors is selected to provide the best dynamic range
when using a TI INA226 converter. In fact, an INA226 converter is installed on the EVM for VDD_CORE,
VDD_MPU, VAM438X_DDR, V1_8D_AM438X, V3_3D_AM438X, and VDDS_DDR power supply rails of
the AM438x. Also, the measurement connections of all the sense resistors are attached to 2-pin standard
headers so that they can be read easily by a multimeter or connected to an INA226 converter EVM.
The AM438x ePOS EVM has the option to access the INA devices through the onboard AM438X I2C0
port by closing jumpers J101 and J102. By default, the INA226 converter is connected to the 5-pin header
J39. See the schematics for more details.
NOTE: The value of the sense resistors for VDD_CORE and VDD_MPU were selected to give better
dynamic range for active power modes, rather than sleep or low power modes. If power is to
be measured for VDD_CORE or VDD_MPU for sleep or low-power modes, then this sense
resistor value must be changed to give better shunt voltage values.
Table 3. AM438x ePOS EVM APM Sense Resistors
Voltage Net Sense Resistor Value
VDD_CORE 0.05 Ω
VDD_MPU 0.05 Ω
VAM438X_DDR 0.05 Ω
V1_8D_AM438X 0.05 Ω
V3_3D_AM438X 0.1 Ω
VDDS_DDR 0.05 Ω
5 Configuration and Setup
5.1 Boot Configuration
SYSBOOT pins on the AM438x can be configured a certain way using a 10-bit DIP switch on the EVM.
This SYSBOOT switch configures the AM438x to different settings. For instance, the boot method of the
processor can be set up by configuring the DIP switch to particular settings. The SW48 DIP switch has the
switches that set SYSBOOT[0...4, 6, 7, 17, 18]. Other SYSBOOT pin settings are done through resistors
pulled either high or low. See the AM438x TRM and data sheet for the actual definitions of each
SYSBOOT signal. Table 4 provides the mapping of the boot strap pin and the corresponding switch bits.
Table 4. SYSBOOT DIP Switches
DIP Switch Bits (SW48) Boot Strap
Bit 1 SYSBOOT18
Bit 2 SYSBOOT17
Bit 3 SYSBOOT7
Bit 4 SYSBOOT6
Bit 5 SYSBOOT4
Bit 6 SYSBOOT3
Bit 7 SYSBOOT2
Bit 8 SYSBOOT1
Bit 9 SYSBOOT0
Bit 10 NC (not connected)

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When the DIP switch is on, then the corresponding SYSBOOT signal is pulled high. When the DIP switch
is off, then the corresponding SYSBOOT signal is pulled low. See the ePOS EVM schematic for more
details.
5.2 I2C Address Assignments
See the first page of the schematic for I2C device addresses.
5.3 I2C ID Memory
The ePOS EVM has a dedicated I2C EEPROM that contains specific identity and configuration information
for that board (see Table 5). In addition, there is available space in each memory for user-specific
configuration information. The part number of the memory device is CAT24C256WI-G.
Table 5. AM438x ePOS EVM EEPROM Data
Name Size (bytes) Contents
Header 4 MSB 0xEE3355AA LSB
Board name 8 Name for board in ASCII "A33515BB" = AM438x ePOS EVM
Version 4 Hardware version code for board in ASCII "1.4A" = rev. 01.4A
Serial number 12
Serial number of the board.
This is a 12-character string: WWYY4P16nnnn, where:
• WW = 2-digit week of the year of production
• YY = 2-digit year of production
• nnnn = incrementing board number
Configuration 32
Codes to show the configuration setup on this board. For the available EVMs
supported, the following codes are used:
• ASCII "SKU#01" = base board for general purpose EVM
• ASCII "SKU#02" = base board for industrial motor control EVM
• Remaining 26 bytes are reserved
Ethernet MAC address #0 6 MAC address for AM438x Ethernet MAC #1
Ethernet MAC address #1 6 MAC address for AM438x Ethernet MAC #2 or PRU #0
Ethernet MAC address #2 6 MAC address for AM438x PRU #1 (if used)
Available 32702 Available space for other nonvolatile codes and data
5.4 JTAG
The AM438x ePOS EVM supports embedded XDS100V2 USB emulation using the microAB connector.
One of the FT2232 ports is used to covert these JTAG signals to USB and the other port is used for UART
signals. The ePOS EVM also has an optional 20-pin CJTAG connector from TI, to support the emulation.
Other JTAG adapters are available on TI's website and can be purchased here.