AM335x General Purpose EVM HW User Guide


 * AM335x General Purpose Evaluation Module (TMDXEVM3358) Hardware User Guide

= Introduction =

This document describes the hardware architecture of the AM335x Evaluation Module (EVM) (Part # TMDXEVM3358) which is based on the Texas Instruments AM335x processor. This EVM is also commonly known as the AM335x General Purpose (GP) EVM.

Description
The AM335x General Purpose EVM is a standalone test, development, and evaluation module system that enables developers to write software and develop hardware around an AM335x processor subsystem. The main elements of the AM335x subsystem are already available on the base board of the EVM which gives developers the basic resources needed for most general purpose type projects that encompass the AM335x as the main processor. Furthermore, additional, "typical" type peripherals are built into the EVM such as memory, sensors, LCD, Ethernet PHY, etc. so that prospective systems can be modeled quickly without significant additional hardware resources.

The following sections give more details regarding the EVM.

EVM System View
The System View of the AM335x General Purpose EVM consists the baseboard, daughterboard, and LCD display board stacked together and connected through standard throughhole connectors. See the pictures below of the EVM.

Schematics/Design/Errata Files

 * HW Documentation - Schematics, Design Files, and other related HW Documentation

Be sure to view the Errata document for important notes = System Description =

System Board Diagram
The complete AM335x General Purpose EVM is partitioned across three different boards for modularity. The GP EVM consists of the baseboard (processor and main power supply), daughterboard (external peripherals), and the LCD display board (LCD and touchscreen).



Figure 3: AM335x EVM System Board Diagram

Processor
The AM3358ZCZ processor is the central processor to this EVM. All the resources on the board surround the AM3358 processor to provide development capabilities for hardware and software. See the AM3358 datasheet and TRM for the details about the processor.

There are system configuration signals, SYSBOOT, that can be set on the EVM to define some startup parameters on the AM335x processor. See the Configuration/Setup section later for more details.

Clocks
The EVM has several clocks to support the AM3358 processor. The main clock for the processor is derived from a 24MHz crystal. An on-board oscillator in the AM3358 generates the base clock and subsequent module clocks as needed within the AM3358 processor. A 32kHz clock for the RTC on the AM3358 is derived from a 32kHz crystal on the board.

Reset Signals
SYS_RESETn is a signal running to several peripherals and AM335x which performs a reset on those peripherals. SYS_WARMRESETn is accerted by the pushbutton and is used to force a reset of the AM335x. AM335x can also pulldown on the RESET_INOUTn signal to cause the SYS_RESETn line to go active.

= Power System =

This section describes how the power supply will be implemented.

Power Source
AM335x Baseboard uses an external AC to +5VDC (rated 2.5A min) power adapter. The switch near to the power cable is used for power ON/OFF. The main power is off when the power switch is in the position away from the power supply jack. The main power is on when the power switch is in the position closest to the power supply jack.



Figure 7: AM335x Power Adapter

Note: When powering this EVM, always use the recommended power supply (CUI/V-Infinity Part Number EMSA050300-P6P-SZ, Model 3A-182WP05) or equivalent model having output voltage of +5VDC, output current max 3.0 Amp, and Efficiency Level V as well as the applicable regional product regulatory/safety certification requirements such as (by example) UL, CSA, VDE, CCC, PSE, etc. Examples of equivalent models include SMI18-5-V-P6 or SWI18-5-N-P6. A power supply is no longer included in the kit. Note: Mounted to this EVM is a UL-recognized component, RoHS-compliant Lithium rechargeable battery (Seiko MS920SE: Nominal voltage 3V, Nominal capacity 11.0 mAh, UL File No. MH15628)
 * This battery should only be replaced by a trained technician.
 * This battery is intended for use at ordinary temperatures where the EVM is not operated above a high temperature of 60&deg;C or below a low temperature of -20&deg;C.



Power Nets
The power nets used in the AM335x Baseboard schematics are listed in the below tables.

Table 1: AM335x Baseboard Power Nets

Table 2: AM335x General Purpose Daughterboard Power Nets

The power sequencing requirements of the AM335X processor (see the AM335x datasheet) are handled automatically by the TPS65910 PMIC.

Power Management IC Power Supplies
The AM335x Baseboard uses the TPS65910 power management IC.

The I2C0 on AM335x is used to control the Smart Reflex port and control port on the TPS65910.

For AM335x, the following power supplies from the TPS65910A are used.

Table 3: AM335x Power supplies from TPS65910A

APM Sense Resistors
The AM335x Baseboard has the following subsystems with current sense resistors. These resistors allow the power to be measured on each power rail to check AM335x 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 base board for both the VDD_CORE and VDD_MPU power supply rails of the AM335x. The other power rails have sense resistors but have their measurement connections attached to 2pin standard headers so that they can be read easily by a multimeter or connected to an INA226 converter EVM.

Note the value of the sense resistors for the VDD_CORE and VDD_MPU were selected to give better dynamic range for active power modes rather than sleep/low power modes. If power is to be measured for VDD_CORE or VDD_MPU for sleep/low power modes then this sense resistor value should be changed to give better shunt voltage values.

Table 4: AM335x Baseboard APM Sense Resistors

= Configuration/Setup =

The GP EVM has many different subsystems to allow development around the AM335x's capabilities. Most of these subsystems are fixed with regard to address locations and pin assignments. However, there are some functions that can be changed by configuring the EVM with switches. For the GP EVM, some of the AM335x pins are connected to different subsystems based on the CPLD profile number that is active. (The CPLD profile number is selected by a 4bit DIP switch on the GP daughterboard.) The CPLD is thus used primarily as a pin mux switch.

Additionally, the AM335x has SYSBOOT pins that can be configured a certain way using two 8bit DIP switches on the base board. These SYSBOOT switches will configure the AM335x to different settings. For instance, the boot method of the processor can be setup by setting certain of these DIP switches to particular settings. SW3 DIP switch has the switches that set the SYSBOOT[0..7] and SW4 DIP switch has the switches that set the SYSBOOT[8..15]. See the AM335x TRM and datasheet for the actual definitions of each of the SYSBOOT signals. The SW3 DIP switch 1 corresponds to SYSBOOT(0), SW3 DIP2 = SYSBOOT(1), etc. The SW4 DIP switch 1 corresponds to SYSBOOT(8), SW4 DIP2 = SYSBOOT(9), etc. When the DIP switch is off, then the corresponding SYSBOOT signal is pulled high. When the DIP switch is on, then the corresponding SYSBOOT signal is pulled low. Also, see the GP EVM base board schematic for more details.

CPLD
The general purpose daughterboard has a CPLD on it with connections to the major AM335x signals. The Altera EPM2210 is used to do active muxing of non-critical signals. It is also available for test logic that may be used for extra-EVM tests. AM335x can communicate and read the configuration of the muxes inside the CPLD by using the I2C bus. I2C0 of the AM335x is connected to the CPLD and an I2C slave is implemented within the CPLD. The I2C address is 0x35.

To control the configuration of the muxes inside the CPLD, user can select the required profiles by using three switches as shown in the below figure. Switches 1 to 3 control the profile that the CPLD, and thus the EVM, operates in. Switch 1 of the DIP switch is the lsb in the profile number and Switch 3 of the DIP switch is the msb of the profile number so possible profiles numbers are 0 to 7. See the pin mux section later in this document for a description of the AM335x pin definitions for each of the 8 profiles. The fourth DIP switch is reserved and should always be off.



Figure 8: AM335x CPLD Profile Switch

I2C Address Assignments
In the AM335x GP EVM boards, each separate board has an I2C ID memory that contains the details of the identity of that board such as it's configuration, etc. (see sections below for more details on the memories' contents). All the ID memories use I2C0 from AM335x (as does the Smart Reflex to the PMIC) so that software can always check I2C0 at the defined I2C addresses for the presence of a board and its contents. Therefore, the baseboard is the only board that has the ID memory set to 0x50, the daughterboard's addresses are all 0x51 (only one daughterboard is ever connected at a time), and the LCD (display board) is at 0x52.

Table 5: AM335x Baseboard I2C Bus Addresses

Table 6: AM335x GP Daughterboard I2C Bus Addresses

Table 7: AM335x LCD A Board I2C Bus Addresses

I2C ID Memory
Each of the three boards in the EVM have a dedicated I2C EEPROM which contains specific identity/configuration information for that board. In addition, there is available space in each memory for user specific configuration information.

The part number of the memory device is pn#CAT24C256WI-GT3.

Table 8: AM335x 15x15 Baseboard EEPROM Data

Table 9: AM335x General Purpose Daughterboard EEPROM Data

Table 10: AM335x LCD A Board EEPROM Data

= AM335x EVM Functional Block Descriptions =

This section describes major functional blocks of the AM335x EVM System.

Board Identity Memory
Each of the boards contains a serial EEPROM that contains board specific data that allows the processor to 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 pn#CAT24C256WI-GT3. See the Configuration/Setup section for details on the data in this memory.

SDMMC0 Connector
The SDMMC0 connector on the Base Board is a Morethanall card socket #MHC-W21-601. This is a standard SD/MMC Card type of connector. It is connected to the MMC0 port of the AM335x processor. Check the AM335x data sheet and TRM for supported card types/densities.

The Pin assignment is as given below.

Table 11: AM335x SDMMC0 Connector Pin Details

Gbit Ethernet
The AM335x baseboard has a Gbit Ethernet transceiver Atheros AR8031_AL1A that is connected to J15.

The reset on the transceiver is driven by the board system reset SYS_RESETn and the individual reset ETHER_RESETn signal that is controlled by GIO SA_GMII1_COL. A 25MHz crystal drives the clock signal for the AR8031. The Ethernet INT pin is sent to the AM335x SA_GMII1_CRS pin for interrupt.

''Note: The GP EVM PCB does not support external delay for the clock signals on the RGMII interface. The AR8031A PHY can be setup to use internal clock delay mode once booting is complete. Therefore there may be problems in function/performance when booting in Gb mode or when running Gb Ethernet Mode before the AR8031A PHY is configured properly. See the EVM Errata.''

The PHYAD pins are left unconnected for setting the PHY's address so it is by default 0x01.

Table 12: AM335x Gbit Ethernet Pin Details

The baseboard has one Gb/s Ethernet PHY and RJ-45 connector for the MII1 port. The RJ-45 connector used to communicate with external Ethernet and for testing with external loopback cable.



Figure 9: AM335x Baseboard Ethernet

USB
The AM335x ZCZ package supports 2 USB ports. The USB ports are on the base board and connected to a microUSB AB connector and a standard A connector. The ESD device TPD4012 and common choke filter ACM2012 (TDK) are used on the USB signals before they are connected to the AM335x pins. The microAB connector has its ID pin tied to ground through a 120K resistor by default so that the port looks like a B device.

Table 13: AM335x USB Port0

Table 14: AM335x USB Port1

COM – Mobile Connectivity Expansion Connector
The AM335x baseboard supports TI MCS COM6/7 form factor wireless boards through the J11 COM connector which is a Samtec card edge type connector pn# MEC. This connector thus supports COM6/7 types of boards, and more details about this connector can be found in the MCS COM6/7 board documents.

The COM connector requires 3.6V 442mA on the power supply. Thus a TPS79501 LDO regulator is used to provide this voltage supply from the base 5.0V supply.

The signals on the COM board are all 1.8V voltage level. Thus voltage translators are placed to convert to/from 3.3V of the AM335x rail for a particular signal which is running at 3.3V.

NOR Flash Memory
The GP daughterboard has flash memory which is a NOR type of flash so that the AM335x's access to/from NOR flash function can be tested. The part number of the memory used is Numonyx pn#M29W128GL which is a 16MB (x16 width) flash memory. The GPMC signals are used to communicate with this memory. The GPMC signals are muxed with other signals in AM335x. Also, several other devices connect to the GPMC signals on the baseboard and the daughterboard. boot from NoR is currently not supported on EVM.

Ambient Light Sensor
The ambient light sensor on the GP daughterboard detects and reports the intensity of light luminescence in the human visual spectrum. The part number of the light sensor used is TAOS pn#TSL2550. The AM335x interfaces to the light sensor through I2C.

I2C1 is used and it is muxed in a TXS0102 using mux signal MUXCTRL_I2C1 which comes from the CPLD (based on the selected profile number).

RS-232 Connectors
The baseboard has one RS-232 connector (DB9 male) for one of the UART's. The general purpose daughterboard has 3 more DB9 RS-232 connectors (male). The muxes on this daughterboard (implemented in the CPLD) allow the UART's on the AM335x processor to be connected to these 3 connectors. UART0 is always connected to the DB9 connector on the base board. See the pin use document later in this user guide for the profiles which support connection of the UART's 1 through 5 to these connectors on the daughterboard. When a profile is selected that enables a UART for use, the UART's are assigned to the DB9 connectors from UART1 to UART5 starting at J10, then to J12, to J14, and then back around to J10. Therefore, when enabled by the profile selection:

AM335x UART1 => J10

AM335x UART2 => J12

AM335x UART3 => J14

AM335x UART4 => J10

AM335x UART5 => J12

Furthermore, these connectors can be connected together (through cable) to provide loopback testing. The MAX3232E is used for the RS-232 level translation.

SDMMC1 Connector
The baseboard has one SDMMC connector for the SDMMC0 port. This general purpose daughterboard has 1 more SDMMC connector for the MMC1 interface.



Figure 10: AM335x Baseboard SDMMC Connector

The Pin assignment of the GP daughterboard SDMMC1 connector is the same as the base board SDMMC0 connector. Refer to that signal table for signal assignments

CAN
The general purpose daughterboard has 1 CAN transceiver and connector for the CAN0 interface. The CAN transceiver that is used is the TI ISO1050 and the connector is a DB9 male connector.

Table 15: AM335x General Purpose Daughterboard CAN Connector Pin Details

A PSM712 transient voltage suppressor and RSZ-3.305HP isolated voltage regulator are connected to the ISO1050 for full industrial connection. The AM335x side line filters are calculated for a max CAN transmission speed of 10MHz.

I2C Expander
This general purpose daughterboard has two I2C I/O expanders. The I/O expander that is used is the TI TCA6408A. The I2C addresses of the expander chip are set to 0x20 and 0x21. Each I/O expander has 4 inputs and 4 outputs.

The use for each of these inputs and outputs:

Table 16: AM335x General Purpose Daughterboard I2C Expander 0

Table 17: AM335x General Purpose Daughterboard I2C Expander 1

ADC Inputs
The general purpose LCD A board has a resistive touchscreen on the LCD (see the LCD/touchscreen section for more details.) The touchscreen uses 4 of the 8 ADC input channels. The remaining 4 channels are connected to isolated connectors so that a signal can be input into them for testing. J8 connector on the GP daughterboard is used to get the analog data from the touch screen and also for manual testing,

Audio Volume Controls
In some of the profiles, audio is enabled. Switches for audio volume control are enabled in these profiles to aid in developing audio applications. These switches are connected to the eOEP. These switches are pushbutton switches to allow realistic actuation of the volume controls.

Accelerometer
An accelerometer is included on the GP daughterboard to allow motion data to be captured/used by the software. The accelerometer is mounted as close to the center of the board as possible to allow the most useful/dynamic data. The ST Micro model LIS331DLH accelerometer is used and is connected via I2C to the AM335x. The I2C address is 0x18. I2C1 is used and it is muxed in a TXS0102.

Keypad
Pushbutton switches (6) are attached to GIO's via a scanning method to allow a keypad to be used. These switches are powered and scanned to see if a switch is pressed (high) or if the switch is not pressed (low on scan line). The hardware debounce capacitors are not installed by default so software must handle the noise associated with the mechanical bouncing of the switches.

Table 18: AM335x GP Daughter Board GPIO keypad signals



Figure 11: AM335x GP Keypad

Haptics Mechanical Vibrator
A Micro Precision pico haptics motor on the GP Daughterboard is used to signal events via mechanical vibration. This is a 304-100 PicoHaptic device which is triggered by a CPLD signal through a FET switch. Thus the profile mode defines which AM335x GIO will turn on this haptics vibrator.

Audio Buzzer
The PUI Audio AI-1027-TWT on the GP Daughterboard is used as an audio buzzer. This is a 2700Hz continuous buzzer that is triggered via a signal from the CPLD through a FET switch. Thus the profile mode defines which AM335x GIO will turn on this audio buzzer.

Temperature Sensor
A TI TMP275 temperature sensor on the GP Daughterboard is used to report ambient temperature. It is controlled by I2C and the I2C address is 0x48.

I2C1 is used and it is muxed in a TXS0102.

NAND Flash Memory
The general purpose daughterboard has a Micron NAND Flash Memory. This is a MT29F2G08ABAEAWP 2Gb 8bit wide flash memory. The footprint is set to allow the 16bit version to be placed instead although there is no plan for this. This memory was placed on the daughterboard to allow active muxing of its signals and allow NOR/MMC1 connection.

Table 19: AM335x NAND Pin Details

Audio
The TLV320AIC3106 audio codec is used on the general purpose daughterboard. This codec is controlled from AM335x by I2C which is at address 0x1B.

LCD Screen
The LCD is a Three Five 7in WVGA (800x480) RGB LCD panel part number #TFC-S9700RTWV43TR- 01B. It is a 24bit RGB TFT LCD with 27 white LED's for backlight (controlled by one power regulator). The connector is FPC 60pin pn #FH28- 60S-0.5SH(05).

The LED backlight on the LCD is controlled by a TPS61081 PWM controlled LED driver.

Resistive Touch Screen
Table 20: LCD A Resistive Touch Screen Pin Details

SPI Flash Memory
There is a SPI based Flash Memory on the daughterboard of the EVM. This is a 64Mb memory Winbond W25Q64CV. See the pin use description for the profile that supports connection to the SPI memory. Due to connection requirements for other devices that share the same pins as the SPI memory, the GP EVM is not designed to operate at the max SPI clock rate as shown in the AM335x datasheet.

WLAN/BT Module
There is a Wireless LAN and Bluetooth card connector on the GP EVM. This connector contains a card with a WL1271 WLAN/BT module and integrated antenna.

= Pin Use Description =

Functional Interface Mapping
Some signals of the AM335x are connected to a fixed device on the EVM where it cannot be changed. Some of the signals of the AM335x, however, are connected to devices on the EVM based on the profile setting.

Since AM335x processor has up to 8 different mux options for each signal, options have to exist on the EVM for allowing the supported subsets of these signals. The pinuse document shows only the signals which are used on the expansion daughterboard.

In the schematics, the AM335x pin names are used for the net names up to the specific mux that connects the signal to the particular function. This is to allow easy knowledge of a single pin's connection to multiple functions through the muxes without burdening the net name to tell all the various functions.

See the additional columns in the pinmux document as there are preset profiles which define what peripherals on the hardware boards are connected and able to be used at a given time.

Pin Use Assignment - Assignment list of pin functions

GPIO Definitions
See the updated pinmux documents which show use case columns for GPIO's. Developer can select and enable pins based on the selective peripheral pins as output or input. For the GP EVM, each single pin is muxed based on the CPLD profile number that is active. (The CPLD profile number is selected by a DIP switch.)

= Board Connectors =

Expansion Connectors
The expansion connector details are listed in the tables below.

Table 21: AM335x EXP0 Connector

Table 22: AM335x EXP1 Connector

Table 23: AM335x EXP2 Connector

Table 24: AM335x EXP3 Connector

LCD Connectors
The connector details of LCD are described below.

Table 25: AM335x LCD Connector 1

Table 26: AM335x LCD Connector 2

This is the touchscreen connector.

Table 27: AM335x Touchscreen Connector

JTAG Connector
TI 20 pin connector... other JTAG adaptors are available on TI e-store and can be purchased from here

= EVM Important Notice =

= ANNEX =

This HUG is prepared by using the following documents as references.


 * 1) AM335x Sitara ARM Microprocessors TRM (SPRUH73)