• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 99 subscribers
  • Views 327 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Some questions about pricing, ram, pin compatibility, startup

bszoke88
Prodigy 40 points
Other Parts Discussed in Thread: AM3894, TPD12S521

Hello

I'm am new to this level of uC usage and I have some questions.

Last summer I got a sample am3894 from TI, but because of limited time and money I could make a 'kit' out of it for further development.

1. Quite to my surprise the then ~35 usd part can now be bought for ~150 usd. Why? TI does not produce these chips any more? dm8168 is listed on TI as 75-100 usd, but costs ~150. Could you please suggest a reseller with good prices and shipping to Europe?

From here on am3894 refers to am3894 and dm8168 parts as well.

2. I have read somewhere that a 4 layer pcb costs 4x a 2 layer of the same size. Would it be possible to make a 2 layered board for an am3894? I think the memory is the most important constraint. With a good design what frequency could be used reliably on a 2 layered board? Please explain.

3. Is the am3894 and the dm8168 pin compatible? Any suggestion to make one pcb for both parts?

4. A year ago I read about how the am3894 can not handle PC memory modules. I believe the last comment was that it was not built for this purpose. Would you please explain why this problem can not be solved in low level software and (5.) whether or not extending the memory controller with an FPGA device could help? (I'm very interested in this because connecting to memory chips is 'messy' for me.)

6. I've read that the am3894 needs a NAND flash to start up. Is it possible to only have an SD card for this? (I've also read that this can be configured.)

7. What is the absolute minimum configuration for an am3894? My opinion would be: HDMI (for monitor), USB (for keyboard), SD card (for boot), DDR memory, JTAG and UART (for programming and testing) and of course power components.

8. Is JTAG necessary to program the am3894?

9. I'm planning to use this kit (if it ever gets ready...) for low power computing using probably Tiny Core Linux. If I had to write a linux driver for a chip, like a usb 3.0 controller, where would I start?

10. I've read about level translator/amplifier/esd chips to be used before a HDMI/pci-e connector. What makes these necessary, when should I use them?

11. How do I connect the pci-e pins of the am3894 for a (maybe) network card to be placed into my board? How do I connect the pci-e pins of the am3894 so that I can place my board into a computer's pci-e slot? Is there a difference?

Please don't just say no, but explain thoroughly why or why not. Don't mind that I wouldn't understand.

Thank you very very much.

bszoke88

  • 0
    TI__Guru**** 170625 points

    Hello,

    I can comment on this questions

    3. DM816x and AM389x are pin-to-pin and software compatible devices. These devices share common IP cores, interfaces, and software support.

    7. Yes, it is possible to boot up and work with SD card. See the U-boot user guide.

    8. JTAG is necessary only for debug.

    9. For USB driver, you can start from here:

    http://processors.wiki.ti.com/index.php/TI81XX_PSP_USB_Driver_User_Guide

    http://processors.wiki.ti.com/index.php/Usbgeneralpage

    Regards,

    Pavel

  • 0 in reply to Pavel Botev
    Prodigy 40 points
    I noticed a mistake in my third line: Last summer I got a sample am3894 from TI, but because of limited time and money I could NOT make a 'kit' out of it for further development. Nr. 3, 6, 8 is solved. Nr. 9 - what about other chips? Is there a general guide for everything else? Thank you. What about the other questions?
  • 0 in reply to bszoke88
    Prodigy 40 points
    Not to be ungrateful or anything, but if you don't/can't help, who can/will?
  • 0
    TI__Guru**** 393215 points
    Hi Barnabas,
     
    1. Quite to my surprise the then ~35 usd part can now be bought for ~150 usd. Why? TI does not produce these chips any more? dm8168 is listed on TI as 75-100 usd, but costs ~150. Could you please suggest a reseller with good prices and shipping to Europe?
     
    Prices quoted on TI site are for 1K quantities, and can be used for budget calculations only. Small quantities normally are at least 50% more expensive.
     
    2. I have read somewhere that a 4 layer pcb costs 4x a 2 layer of the same size. Would it be possible to make a 2 layered board for an am3894? I think the memory is the most important constraint. With a good design what frequency could be used reliably on a 2 layered board? Please explain.
     
    A 2-layer board is absolutely out of the question for dm8168. The datasheet recommends at least 4 layers.
     
    3. Is the am3894 and the dm8168 pin compatible? Any suggestion to make one pcb for both parts?
     
    Yes, they are. You can design a PCB for DM816X and place AM389X on it.
     
    4. A year ago I read about how the am3894 can not handle PC memory modules. I believe the last comment was that it was not built for this purpose. Would you please explain why this problem can not be solved in low level software and (5.) whether or not extending the memory controller with an FPGA device could help? (I'm very interested in this because connecting to memory chips is 'messy' for me.)
     
    PC memory modules nowadays are 64 or 128-bit wide. The DM816X EMIF is 32-bit wide. I haven't heard of anyone trying to extend the EMIF interface through an FPGA, and I sincerely doubt that it is possible at all. If anything, an FPGA working at these frequencies will be so expensive as to make the whole excersise pointless. The DM86X datasheet has a very good design guide for DDR memories.
     
    6. I've read that the am3894 needs a NAND flash to start up. Is it possible to only have an SD card for this? (I've also read that this can be configured.)
     
    Yes, it's possible to boot from SD. And yes, boot options are configurable.
     
    7. What is the absolute minimum configuration for an am3894? My opinion would be: HDMI (for monitor), USB (for keyboard), SD card (for boot), DDR memory, JTAG and UART (for programming and testing) and of course power components.
     
    Depends on intended use, but yes, this is a possible configuration.
     
    8. Is JTAG necessary to program the am3894?
     
    You will need it at least to bring up the board and during DDR memory initial setup.
     
    10. I've read about level translator/amplifier/esd chips to be used before a HDMI/pci-e connector. What makes these necessary, when should I use them?
     
    If you want to have a HDMI compliant connector, you will need a chip like TPD12S521. It does all the necessary ESD protection and level translation.
     
    11. How do I connect the pci-e pins of the am3894 for a (maybe) network card to be placed into my board? How do I connect the pci-e pins of the am3894 so that I can place my board into a computer's pci-e slot? Is there a difference?
     
    You can start by studying the DM816X EVM documentation (http://support.spectrumdigital.com/boards/evm816x/revg/)
  • 0 in reply to bszoke88
    TI__Mastermind 26215 points

    AM3894 is in production, please check with our distributors

  • 0 in reply to Biser Gatchev-XID
    Prodigy 40 points
    Thank you very much for answering. 2. I have read the datasheet, so I know what it recommends. Where exactly is the explanation part in your answer, please? 4. But it has 2 32 bit EMIFs. 2x32 is 64, isn't it?? 5. Forgetaboutit. 11. I have read the EVM documentation. How about answering the latter two questions as well?