• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 98 subscribers
  • Views 960 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.

OMAP-L138 Start-Word sync failure

Jeroen te Paske
Prodigy 30 points

Other Parts Discussed in Thread: OMAP-L138

HI All

I am using OMAP L138 on my custom board and haven't been able to access it properly.

I have copied the design from the evaluation board, except the USB driver. I'm interfacing with a serial cable and a serial to USB interface with the host-PC. I'm able to receive the BOOTME string and see proper communication on the oscilloscope from both TX and RX channel and verified that the baudrate is 115200 baud.

I'm not using CCS, just communicating through command promt with sfh_OMAP-L138.exe.

I'm not getting past Start-Word sync, could anyone give advise?

  • 0
    Prodigy 30 points

    Hi all,

    I've monitored my serial port with a free serial port monitor from HHD and got the following results:

    HEX                                                             ASCII

    Answer: (From L138 to host PC)
    00 42 4F 4F 54 4D 45 20 00                        BOOTME

    Request: (From host PC to L138)
    58                                                                 X

    As I understand from http://www.ti.com/lit/an/sprab41d/sprab41d.pdf the host repeatedly sends transmit-start-word (XMT_START) to the L138.

    The error message during communication with the L138 with sfh_OMAP-L138.exe "Read error! (The operation has timed out.)"

    Apperently the transmit-start-word is timing out???

    Someone any suggestions here?

     

  • 0 in reply to Jeroen te Paske
    TI__Mastermind 43955 points

    Hi Jeroen,

    The serial flasher utility is provided for TI EVMS (OMAP-L138, C6748, and AM1708 families of devices)

    If it is a custome board, make sure that the required modifications mentioned in the WIKI page http://processors.wiki.ti.com/index.php/Serial_Boot_and_Flash_Loading_Utility_for_OMAP-L138#Modifications_for_Custom_Boards are done in the source code of the sfh_OMAP-L138.

    And also, in the same wiki page it is mentioned that "If the oscillator used with the device does not match the one used on the EVM (e.g. on a custom platform), the baud rate assumption may be incorrect. "

     

    Regards,

    Shankari

    -------------------------------------------------------------------------------------------------------

    Please click the Verify Answer button on this post if it answers your question.
    --------------------------------------------------------------------------------------------------------

  • 0 in reply to Shankari G
    Prodigy 30 points

    Hi Shankari,

    I've found it, I had too large resistors in series with the UART TX and RX lines, I lowerd them to 100Ohm, and now I'm able to load the bootloader. Then I got the next issue in communicating with the DSP, it was for ever waiting for SFT on the OMAP-L138.

    I discovered that I have picked the wrong manufacturer code for the NAND-flash ((MT29F1G08ABBDAHC) on my custom board and found out that TI has done an update on the schematic and the BOM of the L138/C6748 Development Kit (LCDK) about the NAND-flash (MT29F4G16ABADAH4).
    There are three differences between the two NAND-flash types:
    1. first one is 1Gb and second is 4Gb
    2. first one has a device width of 8-bit and second 16-bit
    3. first one has a supply voltage of 1.8V and second 3.3V

    I think the suply voltage is the major issue here, because the supply group of the DSP which is communicating with the NAND is also on 3.3V. I will try to replace the NAND-flash on my custom board and will update this topic when it is ready.

    Regards,

    Jeroen

     

     

     

  • 0 in reply to Jeroen te Paske
    TI__Mastermind 43955 points

    Hi Jeroen,

    Great!. Thanks for the update.

     

    Regards,

    Shankari