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spi mode TMS320C6748

shush perez
Prodigy 180 points
Other Parts Discussed in Thread: TMS320C6748, OMAP-L138

Hi all!

I'm working on a project based on  TMS320C6748

I want to  to use the Serial Peripheral SPI_0 . For such operation I will hand the SPI_0 driver supported by ti , I see that there is a gap between the first byte and the remaining bytes depends  the operating mode it was selected ,why does this driver operate on this strange way ??. What must I modify  to be able to work under bursting mode but all byte from the first to last byte on consecutive way opearaion .  /....................

Every help will be appreciated.

Shush

  • 0
    TI__Expert 8785 points

    Which driver are you using?  Is it the one provided in BIOS?  What type of operations are you performing (reads, writes, etc)?

    --Christina

  • 0 in reply to clam
    Prodigy 180 points

     

    Dear Christina

    I am using a the last version of driver provided in BIOS  .

    When is used the spi driver supported by ti ( to send 5 bytes :   1ADD+4 DATA ) the result is shown in the att file  :

    First cs : 6us (1st byte= ADD) after that a long gap why ??? and finally is sent the remaining  4 bytes (6us) in total

    All cycle (M1—M2 logic) 25.91 us , how is possible when the set time clk is 50 Mhz (max frq allowed 20 ns)   so estimated time  8+32bit= 40 bit so 40x20ns 800 ns like 1us but no  25us ,what happened here is it impossible work in this way   . my require time is <1.2us = time cycle .

    I need burst 5 bytes consecutively   

    I hope your help and cooperation

    Shush 

     

     

  • 0 in reply to shush perez
    TI__Expert 8785 points

    After asking some SPI hardware experts, they do not see why there is a gap in between the transactions.  From their experience, it was mostly continuous (with very small equal delays between the transactions).

    I'm going to move this to the BIOS forum.  Hopefully, the people who developed the driver can see if there are some constraints with the driver.

    --Christina

     

  • 0 in reply to clam
    Prodigy 180 points

    Dear Christina

    At first thanks for your cooperation .

    I need to know what must I do to send 5 bytes so 1 bytes add+4 bytes data  in less than 1.2 us , according to data sheet must be less than 900ns but no 25 us , so pls . I need somo example to check on my EVM: OMAP-L138.   This answer will be important for all users that need operating the SPI PORT at high frequency .And no with the actual driver that opearates like was named and showed ( 26 us to send 5 bytes !!!!!!!!).

    Thanks you and I am waiting some feedback ASAP.

    Shush..  

      

  • 0 in reply to shush perez
    TI__Expert 8785 points

    Have you tried running the rCSL example inside the BIOS package?  It is a low-level example that does not use BIOS.  It is located in pspdrivers_01_30_01\packages\ti\pspiom\cslr\evm6748\examples\spi. 

    Can you try running this example to see if the time improves?  If it does, you can use this example and modify it for your desired application.

    --Christina

  • 0 in reply to clam
    Prodigy 180 points

    Dear Christina

    I checked those example on my EVM ( SPI_0 port ) and it is not working correctly , I do not see CS,CLK,DATA toggle . Could you check this example in your EVM OMAP-138 , In my case no work  , if it function in your work , Please so send me the whole project , to check in my EVM .

    Thanks

    Shush