HARDWARE QUESTIONS JETSON TX2i

Hello,
I want to use the JETSON TX2i on a carrier that’s already developed and my ability to change features is limited. On the other hand I wish to be as ready as possible for any contingency in the integration. Would love to get some answers and clarifications.

  1. Is the RAM soldered on the module?
  2. Is it possible to order a module without on board memory and use only an external SATA interface for memory?
  • Clarify, to have the OS on an external SATA memory
  1. Is it possible to work with 10/100 ethernet using only 2 of the GbE pairs? If yes, does it require some special configuration or is plug and play?
  2. In order to work with 2 PCIe controllers (1x4, 1x1) Is special configuration needed or is it plug and play?
  3. What is the use of the JTAG interface? Can it assist in integration? If yes, in what way? which hardware is used? can the OS be installed via jtag and not just via USB?
  4. POWER SEQUENCE - My board has a FPGA and the POWER SEQUENCE in the JETSON’s datasheet doesn’t comply with the PCIe requirement to have the end point (my FPGA on the carrier) on prior to the root-complex (JETSON). How do you settle this issue? Is it possible there’s a different power sequence available for this kind of setup?
  5. My system doesn’t have: PCIe_WAKE, POWER DOWN SEQUENCE, PUSH BUTTON (FOR POWER). Is it possible to work without these features?

Thank you!
Best Regards,
Sheran

Hi, please find answers below. For most questions you can find the answers in OEM DG, module datasheet, devkit spec and ref SCH of carrier board in DLC, please read them first before make design.

  1. Is the RAM soldered on the module?
    -Yes.

  2. Is it possible to order a module without on board memory and use only an external SATA interface for memory?

  • Clarify, to have the OS on an external SATA memory
    -No, no custom module for sale.
  1. Is it possible to work with 10/100 ethernet using only 2 of the GbE pairs? If yes, does it require some special configuration or is plug and play?
    -Yes, it is possible and no other specials required.

  2. In order to work with 2 PCIe controllers (1x4, 1x1) Is special configuration needed or is it plug and play?
    -No other hw required, but possibly need to tune the driver of external devices.

  3. What is the use of the JTAG interface? Can it assist in integration? If yes, in what way? which hardware is used? can the OS be installed via jtag and not just via USB?
    -Jtag is for some deep debug, it is not much useful to general customer, you can just ignore it.

  4. POWER SEQUENCE - My board has a FPGA and the POWER SEQUENCE in the JETSON’s datasheet doesn’t comply with the PCIe requirement to have the end point (my FPGA on the carrier) on prior to the root-complex (JETSON). How do you settle this issue? Is it possible there’s a different power sequence available for this kind of setup?
    -Is it possible to change your design to power on your FPGA first? The power on sequence of TX2i is fixed.

  5. My system doesn’t have: PCIe_WAKE, POWER DOWN SEQUENCE, PUSH BUTTON (FOR POWER). Is it possible to work without these features?
    -Power button is NOT must as there is auto-power-on option, power down sequence is recommended as you can see the introduction in OEM DG, PCIe_wake depends on the PCie device you use, and so the driver of it.

Thank you.

About the power sequence, in my current design the FPGA is “on” prior to the root complex. But since it’s on the carrier board it doesn’t comply with JETSON’s demand to have it’s power on prior to the carrier’s power.

my sequence: Main power ON --> internal power sequence for FPGA --> release the “power_bad” indication so the JETSON will power up

can you help clarify?

About the memory (even if it stays on board), is it possible to have the OS only on the external SATA and not use the on board memory at all?

Hello,

Would love to get a clarification on the above questions.

Also -

  1. Without power down will the module be damaged?
  2. Will the module work properly without VDD_RTC? If not connected should it stay floating?

Thank you,
Sheran

  1. Jeston power on sequence is fixed, better to follow it.
  2. Boot from SATA is not supported.
  3. Power down sequence is necessary and some kinds of it will auto run, in order to meet the Power Down requirements, discharge circuitry is required.
  4. Yes, leave it floating is OK.

Thank you!

  1. Boot from SATA is not supported, is it possible to load files and application from the external SATA?
    Or is it used only for storage?

  2. What do you mean by “some kinds of it will auto run”?
    I don’t have a warning before system power down and can’t support power down sequence. What will happen to the module in such scenario?

Thank you,
Sheran

The stages of boot prior to Linux starting do not have SATA drivers. Thus if you have content required to boot the content would become unavailable and no boot would be possible. Once the Linux kernel is running (which has SATA drivers) you can use the disk any way you want.

thank you!

Another question regarding the I2C interface.

Can all interfaces that are described as general usage, be used as master on the bus?

All I2Cs are master only.