TDK System Components
- Martin Welford
This section has details on each of the system components that makes up the Topaz i.MX25 Development Kit (TDK)
The block diagram below (click for larger view) shows the main components on the Development Kit board, and how they are connected. This page details the main components in this diagram.
For details on specific i.MX25 features, please refer to the Topaz CPU Reference Manual.
Topaz CPU Module
The Topaz CPU Module is at the core of the Topaz Development Kit. The Topaz includes a Freescale i.M25 processor, 64Mbytes of SDRAM and 128Mbytes of flash, a power management chip, and Ethernet PHY.
The block diagram illustrates how the various functions of the Topaz CPU are used in the Development Kit.
User Interface Components
LCD and Touch-Screen
The Topaz CPU has an integrated LCD controller and touch-screen controller. The Development Kit LCD expansion connector includes these signals, along with SPI, I2C and power to enable the connection of a variety of displays. LCD options available include 4.3" and 7" touch screens. You can use the specifications in this document to develop an adapter board to test different displays.
User Button, switches and LED
The Development Kit includes a single push button connected to a GPIO for use by user applications. There is also a DIP switch and a LED that are connected to GPIO for this purpose.
Item | GPIO |
Push-button switch | 4-4 |
LED | 3-17 |
DIP switch | 1-4 |
Accelerometer
The Topaz Development Kit includes a Freescale MMA7660FC Accelerometer. This is a low-g accelerometer which include features for determining tilt and orientation of a device. It is connected to the I2C bus and has an interrupt signal connected to GPIO 1-5.
Audio
A Freescale SGTL5000 audio codec is included on the Topaz Development Kit. It provides stereo audio input and output, and is connected to the Topaz CPU via the AUD4 signals for audio and I2C for control. The headphone output signals go to the audio connector on the Development kit, and the other interfaces (line in and out, and microphone in) are available on the EXP1 header.
Analog Inputs
There are 3 ADC channels available for application use. These are present on the EXP2 connector. Refer to the Topaz CPU Reference Manual for details on the capabilities of these inputs.
Configuration Switches
There are 4 configuration switches on the Topaz Development Kit.
Switch these to the ON position (label side) to enable.
Switch | Label | Function |
|---|---|---|
1 | BOOT 0 | When enabled, these switches put the board into boot-loader mode. Use the supplied software and cable to download new firmware to the board. For normal operation these must be in the disabled position. |
2 | BOOT 1 |
|
3 | LION | LiIon signal to the Topaz Power Supply. Enable this signal if you are powering the development kit from a LiIon battery. |
4 | GP 1-04 | Switch available for application use. When enabled the GPIO line is pulled low. |
Reset
The Reset button is connected to the MODULE_RESET signal on the Topaz CPU Module.
Communications Components
USB Host
The Development Kit includes a type A connector for attaching USB peripherals. This is a full speed (12Mbps) port. To use this port with a device that requires power (5V) you must be powering the Topaz with 5V.
USB OTG
The USB OTG port is a high-speed (480Mbps) port which can operate in host or function mode. When using the Development Kit with 4.3" or small displays, this port can also be used to power the system.
To use this port in host mode, you will need to provide 5V power via the alternative power connectors.
Serial Ports
The i.MX25 has 5 serial ports, and the Topaz Development Kit makes 4 of these available as:
- RS232 level signals on a DB9 (UART1)
- Logic level (3.3V) signals on EXP2 (UART2, UART3 and UART4)
The serial port signals are also multiplexed with other functions. The details are available in the Topaz CPU Reference Manual.
Ethernet
The Topaz Development kit provides 10/100 Ethernet via a RJ-45 connector.
The majority of the Ethernet functionality is implemented on the Topaz CPU module (MAC as part of the i.MX25 + an external PHY). The only additional components on the Development Kit are a few resistors and capacitors, and a RJ-45 connector with integrated magnetics. The RJ-45 connector includes 2 status LEDs.
- Orange: Link Status
- Green: Network Activity
File Storage
Internal Flash Storage
The Topaz CPU module includes a NAND device that is typically configured to provide file storage for your operating system of choice.
SD Card
The Topaz Development Kit includes a SD card slot which support standard sized SD memory and SDIO cards.
Expansion
The primary functions of the i.MX25 have been included on dedicated connectors, with the remaining pins made available on 0.1" headers. These are labelled EXP1, EXP2 and EXP3. The Topaz CPU Reference Manual is the best place to look for specific details on each function. The primary use has been labelled on the Topaz Development Board, however most signals can be used for more than one purpose.
When attaching to the EXP connectors, be aware that some signals are 1.8V only.
Power Supply
The Topaz Development Kit can be powered from:
- USB mini-AB connector.
- Barrel connector (J12)
- 2 pin header (J13)
The Topaz Development Kit will function with voltages ranging from 2.7 to 5.5V. A protection circuit is included to prevent higher voltages from damaging the board.
We recommend that 5V is used whenever possible as this enables the USB Host ports to be used.
JTAG Connector
A standard 20-pin ARM JTAG connector is present to allow firmware and application debugging using appropriate tools.