MCU-PLUS-SDK-AM263X: Low power mode

Hi Saman,

As you mentioned you need to clock gate the modules that are not used, this is applicable to cores as well as peripherals. 

You could use (MSS_RCM,MSS_TOPRCM,C2K_GLOBAL_CTRL space)

<module>_CLK_GATE registers  to clock gate the modules

If I understand the requirement correctly you would like to capture ADC data every 10 ms ? If so you could have a RTI timer set to trigger ADC read every 10ms and rest of the time you could put core to WFI mode. Is this the only processing done on R5F ? 

Best Regards, Shiv

Yes, that is correct, Can you help me how to put the core into WFI mode and how the core will be out of WFI mode?

By the way, is there any example or sample code or API showing how to change <module>_CLK_GATE in order to power down each module?

THanks

Saman

Hi,

From R5F TRM:

For WFI, the transition from Standby mode to Run mode is caused by:

• the arrival of an interrupt, whether masked or unmasked

• a debug request, whether debug is enabled or disabled

• a reset.

I will check and come back on putting core to WFI mode.

On programming the CLK_GATE registers

You could simply write 0x7 to each of those registers and poll the same register to see 0x7.

Best Regards, Shiv

Hi Shiv,

Where can I find the list of _CLK_GATE registers? Is the only thing writing 0x7 to those registers?

and how to ungate it?

I am waiting for how to put core into WFI mode. 

Is the WFI mode a kind of sleep mode which puts the core in low power mode and waiting for interrupt to woken up again?

Saman

Hi Saman,

You can find the registers list in https://www.ti.com/lit/ug/spruj42c/spruj42c.pdf 

The Clock Gate registers are mainly present in MSS_RCM, MSS_TOPRCM, and GLOBAL_CTRL in CONTROLSS.

Writing 0x7  to _CLK_GATE registers will gate the clocks and clearing would un-gate.

WFI is one of the STANDBY modes. Please refer to 6.2.4.1 Overview of Device Power Modes in TRM 

https://www.ti.com/lit/ug/spruj17c/spruj17c.pdf

Yes when you put the core in to WFI mode it would enter the standby mode and wait for Interrupt.

More on Standby /WFI from ARM TRM (DDI0460C_cortexr5_trm)  as well:

https://developer.arm.com/documentation/ddi0460/c/Power-Control/Power-management/Standby-mode?lang=en 

Please let me know if this helps.

Best Regards, Shiv

Hi Shiv,

Thank you so much for help,

I have been said before by the TI expert at the E2E forum that the example for the standby mode and how to put device into WFI mode will be available in "MCU PLUS SDK version 08.06.00 (scheduled for Q1-2023)" do you have any information regarding this?

Thanks 

Saman

Hi Saman Mardani,

Saman Mardani said:

I have been said before by the TI expert at the E2E forum that the example for the standby mode and how to put device into WFI mode will be available in "MCU PLUS SDK version 08.06.00 (scheduled for Q1-2023)" do you have any information regarding this?

We do not have plan to integrate this as a part of 8.6 release. We would plan it in 9.x release which is post 2023 release for which the timelines are not very clear at this moment.

Although just to understand the system level use case for you, can you explain the following items to us ?

Can you help us populate this based on your use case ? Is this what is required out of this experimentation ?

Best Regards,
Aakash

Yes this is my required use-case, actually there are more than one SPI and ADC in normal mode. So I do not have exact calculation of power usage during normal mode. 

Hi Saman,

I need a little more time to come back to you with these details. For now, the ETA that we can suggest is 24th Feb. But we will reach out early incase of any earlier details.

Best Regards,
Aakash

Hi Aakash,

Thanks for the reply,

I am looking forward to 24th Feb.

BR

Saman

Hi Saman Mardani,

I am working on the same but seems like it would most likely be pushed to 1st Mar. Apologies for the inconvenience.

Best Regards,
Aakash 

Hi Aakash

Is there any update on this issue?

Thanks you

Hi Saman Mardani,

We have an application created according to the requirement.

https://tidrive.ext.ti.com/u/8w_m5MaP5vvhD-bp/85306e93-07a3-4acf-8ae1-3841807a04e8?l

But we still need to check the power consumption on the same. We are working on the same but we still don't know about the timeline here. If you try this on your end, do let us know. We can help on the same.

Best Regards,
Aakash