BMSKTOPASA900

↑ Features  #

• 3.5" TFT display with touch screen
• 10/100 MBit fast ethernet connection
• USB 2.0 (Host and Device)
• RS232
• Excellent sound quality (audio DAC via I2S)
  input and output jack
• Two SD-card sockets (SD-Host controller and via SPI)
• Joystick
• JTAG interface
• Memory:
  • 64 MByte SDRAM
  • 32 MByte NOR Flash
  • 256 MByte NAND Flash
• Single power supply (5V-35V or simply via USB)
• Extensive software support by 3rd party tools
  • Segger for Graphic Libraries/OS and more
  • Development Tools from IAR, Keil and Atollic
  • Linux support is now available from kernel concepts
• Schematics and Layout Data provided by Toshiba
  • Designed and Produced in Germany
  • Contact us for more information

↑ Block Diagram  #

↑ Hardware Caveats  #

While working with this board we discovered some stumbling blocks we would like to help you avoid. Please keep the following issues in mind.

• SPI0 and I2C0: Despite the fact that the pins for SPI0 and I2C0 are clearly marked on the soldering pads they are not available there by default. On the bottom side of the Topas A900 you'll find two groups of solder jumpers, which have to changed to be able to use the respective port at the soldering pads. By default SPI0 is connected to the SPI SDcard slot, I2C is connected to controls for the USB power supply.
• Seven segment display and joystick: Contrary to the Topas 910 Joystick and seven segment display are not connected directly to Port A and B of the CPU. The reason for this is, that the CPU only provides 4 bits each on Port A and B, joystick and seven segment display however would need a few more pins. As a workaround there is a CPLD connected inbetween, which translates joystick movements into encoded values on Port A and does a hexadecimal conversion of the port B value to the seven segment display. Depending on the usage scenario this can hamper an arbitrary use of port A and B.
• Booting from NAND: The CPU internal boot rom uses pin PT7 to determine which kind of NAND flash is connected. On the Topas A900 this pin is floating, which means that it can be a bit of a hit or miss. If booting from the NAND on the Topas A900 is required PT7 needs to be pulled down to GND with a pull down resistor. Booting from NOR flash is not affected.
• I2C0 and I2C1: Note that the text for the solder pads to PF6 and PF7 is swapped. The same holds true for PC6 and PC7.