DM8168 Power down DSP

Hi Nithin,

       If you are not planning to use the DSP I would try just not loading the firmware into the DSP when the system boots, it is removing the line that uses the firmware_loader to load the file dm816x_c6xdsp.xe674 in case of the EZSDK, have you tried that?

-David

Hi David,

I'm able to find dm81xx_c6xdsp_debug.xe674 in below path,

usr/share/ti/rpe/

But I'm not able to find script file where they are using firmware_loader to load this firmware.

Can you please let me know in which script file this is done and where this file is located.

Thanks and Regards,

Nithin

Hello,

If you are using EZSDK:

The script is load-hd-firmware.sh in /usr/share/ti/ti-media-controller-utils folder.

By default the DSP firmware (dm81xx_c6xdsp_debug.xe674) is not loaded!

You could check is the DSP firmware is loading when the board is booting.

Best Regards,

Margarita

Hi Margarita,

No this firmware is not getting loaded when board boots.

And one more thing I'm not using this script file, I commented all firmware loading lines present in this file.

I have one doubt, If we won't load "dm81xx_c6xdsp_debug.xe674" this firmware, whether this means that DSP is in power down state.

If yes that is what I want. If no please let me know how to do DSP power down.

Thanks and Regards,

Nithin

Hello,

You could check in the TRM (Technical Reference Manual):

1.3 C674x DSP Subsystem & Power Management


Best Regards,

Margarita

Hi Margarita,

Thanks for the reply.

I have one more doubt, If I disable DSP clock what will be the result of this.

Is this power down the DSP, because in TRM it is mentioned like PDC initiates power down DSP (clock gating).

Thanks and Regards,

Nithin

Hi Margarita,

If you check below TI link it is mentioned that for adding power management functionalities for DSP in DM814x processor patch file is given.

http://processors.wiki.ti.com/index.php/DM814x_AM387x_PM_Suspend_resume_overview#Turn_OFF_Power_domains

If you check this patch file in suspend function

    clk_disable(dsp_dev->ick);
    clk_disable(dsp_dev->fck);

this code is sitting.

Thanks and Regards,

Nithin

Hi All,

I have one doubt regarding DSP in DM816X processor.

If DSP is not used in our project, i.e firmware related to DSP is not loaded, whether DSP will be in

power-down state or it will be in Idle state.

Thanks and Regards,

Nithin

Nithin,

Nithin kumar2 said:

If DSP is not used in our project, i.e firmware related to DSP is not loaded, whether DSP will be in

power-down state or it will be in Idle state.

You can check the DSP power state (OFF, Idle, ON) through reading the corresponding PRCM register.

In the below e2e thread you will find info regarding the DSP power off in the DM814x device. I think should be similar for DM816x device.

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/256582.aspx

Regards,
Pavel