• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 99 subscribers
  • Views 1091 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 clock on 450 MHz instead of 300 MHz

Royke
Intellectual 510 points
Other Parts Discussed in Thread: OMAPL138, OMAP-L138

I have a question. In the datasheet is written that  he can be clocked to 375/456-MHz, but I can't find how to make the clock higher than 300 MHz.
I am now running at 450 MHz (find some information somewhere on the internet, forgot where) by doing the following:

  • changed the gel-file:
     added 
    Set_Core_450MHz() {
        device_PLL0(0,36,1,0,1,17,5);  // Pll: 36 x 25 / 2 = 450
        GEL_TextOut("\tPLL0 init done for Core:450MHz, EMIF:25MHz\n","Output",1,1,1);
    }
    and called it in  OnTargetConnect()
  •  
  • added to the .tcf file
    bios.GBL.CLKOUT = 450.0000;

This worked, then I was using this clock as source for the McBsp and saw that the McBsp was not clocking on the frequency I expected.
I digged into it and found in the chip support Library in the file soc_OMAPL138.h the following line:
#define CSL_SYSCLK_1_FREQ                   (300000000u)

This can't be good if I am running on 450 MHz. 

So my question is simple:

What do I have to change to run on a other than 300 MHz clock? 

 

 

 

  • 0
    TI__Genius 14545 points

    Royke -

    Royke said:
    This worked, then I was using this clock as source for the McBsp and saw that the McBsp was not clocking on the frequency I expected.

    When you change the main frequency of the system, this will affect clocking to all your peripherals. The McBSP sample rate should change will the main system clock change.

    You will need to reconfigure the McBSP clock dividers with the new system clock frequency in mind to achieve the sample rate you expect. I would look into the Sample Rate Generation Register (SRGR) to make sure you have the McBSP clock dividers set accordingly to the change in your system clock frequency.

     

    You can find the clocking diagram for OMAP-L138 on page 85 of SPRUGM7D for further reference.

     

  • 0 in reply to dabuan
    Expert 2250 points

    I changed GEL file from 300MHz to 456MHz for LogicPD board

    It works file with StarterWare as I'm able to update and recompile the library

    However, it does not work for me with pspdrivers_01_30_01. I found the header and change 300000000 to 456000000, but it does not pick up the change

    Actually I corrupt the header file by a illegal chars, say "Hello" and still I'm able to compile it successfully for "UART" lib!!!

    How to recompile PSP lib ?

    Thanks,

    ~Duy-Ky

  • 0 in reply to Duy-Ky Nguyen88210
    TI__Guru** 116170 points

    Could you try this GEL file and let us know if this worked for you.

    http://processors.wiki.ti.com/index.php/OMAP-L1x_456MHz_GEL

    As far as I know the PSP drivers perhaps don`t control the device clock but only need that information to compute appropriate dividers for the IO data rate settings. I can confirm this and get back to you. Could your try out the GEL file provided on that wiki.

    Regards,

    Rahul