OMAP-L138: How we can change clock frequency in TI-RTOS NDK2.25

Hello Ashish,

You can change the clock frequency using CCS GEL file. Since you're working with the CCS project, I assume you can connect to your board through CCS. If not, please follow these instructions to do that.

Once you can connect to AMR9_0 core, go to CCS > Scripts > Frequency Settings > Core_456MHz_mDDR_150MHz as shown below:

After this script is run, the ARM core should be set to 456MHz. 

To change DDR address, since you're using the BIOS based project, you'll need to change the platform setting.

1. Go to CCS > Project > RTSC Tools > Platform > Edit/view.

2. Put C:\ti\bios_6_76_03_01\packages in the Platform Package Repository and choose ti.platforms.evmOMAPL138 as the Package Name. Choose "GPP" or "CPU" as the CPU core and then click "Next".

3. Change DDR Base from 0xC3000000 to 0xC4000000. 

4. Click "Finish" and let it finish building the platform.

5. Rebuild your project and you should see DDR origin address is 0xc4000000 in the map file, as shown below:

MEMORY CONFIGURATION

         name            origin    length      used     unused   attr    fill
----------------------  --------  ---------  --------  --------  ----  --------
  L3_CBA_RAM            80000000   00020000  00000000  00020000  RW X
  DDR                   c4000000   01000000  00182564  00e7da9c  RW X
  IRAM                  ffff0000   00002000  00000368  00001c98  RW X

Regards,

Jianzhong

Dear Jianzhong,

Thanks for your reply

We did as per your reply and the ddr origin and length were also changed, but when we changed the clock frequency then the UART2 is not working properly as expected and some garbage characters are printing on the tera term,

So please let us know that what changes we need to do in case of UART2 to work properly

Also we need to put this appl.bin file in the NAND flash to work

Regards,

Ashish

Hello Ashish,

Was UART2 working properly before you changed the clock frequency?

Regarding NAND flashing, please check this app note. The download link for the serial boot and flash loading utility was missing in the app note but is provided here: https://sourceforge.net/projects/dvflashutils/files/OMAP-L138/v2.40/.

Regards,

Jianzhong

Hello Jianzhong,

Yes uart is working on 300 Mhz frequency and when we changed the clock frequency to 456 Mhz via gel file as you have mentioned our uart is showing some garbage character on tera term

Note: We are using arm core or omapl138 for programming

Regards,

Ashish

Hi Ashish,

Thanks for the confirmation. I think you also need to change the clock frequency for UART, which is defined in pdk_omapl138_1_0_11\packages\ti\drv\uart\soc\omapl138\UART_soc.c:

        300000000/2,  /* default UART frequency, system clock/6 */

This should be changed to 

        456000000/2,  /* default UART frequency, system clock/6 */

Then you'll need to rebuild UART LLD library according to the instructions here.

Regards,

Jianzhong

Please also refer to this thread for more information.