RTOS/AM3358: Changing MPU frequency

Hi Alexander,

You can configure the BIOS cpu frequency in the .cfg file to match the frequency that the CPU is running at by adding this to your .cfg file. For example 550MHz:

BIOS.cpuFreq.lo = 550000000;

I assume you have set your MPU frequency in the GEL file as well. If you are unsure on how to do that, please let me know.
Hope this helps.

Lali

I was aware of how to change the platform settings but your comment on setting the speed in the GEL file seems more in line with what I need to do.  (The issue I had was setting the CPU frequency in the highlighted area you show above would create a mis-match with, I am assuming the GEL file) and not run.

What is the method of changing the MPU frequency in the GEL file and how do I incorporate that into my build? Do I need to rebuild my board files after I change the GEL or does it get compiled when I build my CCS project?

Thanks for the help!

Alexander,

You can define a GEL file that can be loaded on the core when its connected in CCS as illustrated below. You can get to this window by double-clicking your CCS BeagleBone Black (BBB) target configuration and going to the advanced tab.

Once you have launch the target config and connected to the A8 core, see the screenshot below on accessing the GEL hot-menus.

The console will spit out the initialization messages as the GEL loads. Here's a good wiki that discusses GEL files in general if you are interested http://processors.wiki.ti.com/index.php/GEL 

Lali

This is good information but not was I was asking about.  I need to change the platform clock rate shown in this view to actually change what the processor speed is running at for my project, correct?  See screenshot below:

It appears  that I need to change this via Project --> RTSC --> Platform --> edit/view, correct?

I looked into this but don't know where the files are stored for me to view them.  If I am way off and don't need to do any of this, please let me know.

Alexander,

To change this setting:

• Project>RTSC Tools>Platform>Edit/view
• In Platform Package Repository, navigate to C:\ti\bios_6_52_00_12\packages
• ti.platforms.evmAM3359 and click next.

Here you manipulate the CPU that's in the platform information section of XGCONF.

Alternatively, you can also set the CPU frequency in the .cfg file by inserting the below line. This will override the settings from above.

BIOS.cpuFreq.lo = 550000000;

Keep in mind that whatever CPU setting you have here must match what you set in the GEL or secondary Bootloader (SBL), otherwise you will have incorrect timing of your clock ticks.

Hope this answers you question.

Lali

Alex,

To set the MPU to NITRO mode, you need to change the PMIC voltage by sending I2C commands to increase the core voltage and then scale the frequency. This functionality can be done using power management(PM) driver that we provide in the Processor SDK RTOS. The PM LLD comes with a PMRTOS measurement example designed for AM335x GP EVM that demonstrates setting the core to different OPP. The LLD and example can be located in the PDK at the following location PDK_INSTALL_PATH\packages\ti\drv\pm\examples\pmrtos_measurement 

Documentation:
processors.wiki.ti.com/.../Processor_SDK_RTOS_PM
www.ti.com/.../spraca5.pdf

Please review the collateral and let us know if you have any questions regarding the same.

Regards,
Rahul

Note: The example has been created with the AM335x GP EVM

The DPLL setting for AM335x NITRO MODE are provided in the driver and also in the spreadsheet that we have provided in the board porting package.