AM625: Power rail configuration in Linux

Koichiro Tashiro

Part Number: AM625
Other Parts Discussed in Thread: SYSCONFIG, SK-AM62-LP

Tool/software:

Hi,

My customer has a question for power rail configuration in Linux SDK.
There are some differences in voltages in each power rail on the customer's board.
He found there is SysConfig tool available to configure some of these power rails, but he wants to change them manually in the code.

Here is a table shows differences between SK-AM62LP and the custom board.

TI System Configuration Tool Available	Power rail	SK-AM62LP Configuration	Custom board Configuration
Yes	VDDSHV0	3.3V	3.3V
Yes	VDDSHV1	1.8V	3.3V
Yes	VDDSHV2	3.3V	3.3V
Yes	VDDSHV3	3.3V	3.3V
Yes	VDDSHV4	1.8V	1.8V
Yes	VDDHSV5	3.3V/1.8V	3.3V/1.8V
Yes	VDDSHV6	1.8V	3.3V
Yes	VDDSHV_MCU	3.3V	3.3V
Yes	VDDSHV_CANUART	3.3V	3.3V
-	VDDA_TEMP0	1.8V	1.8V
-	VDDA_TEMP1	1.8V	1.8V
-	VDDA_PLL	1.8V	1.8V
-	VDDA_DDR_PLL0	0.75V	NA
-	VDDA_MCU	1.8V	1.8V
-	VDDA_1P8_OLDI0	1.8V	1.8V
-	VDDA_1P8_OLDI0	1.8V	1.8V
-	VDDA_CORE_USB	0.75V	0.75V
-	VDDA_CORE_CSIRX0	0.75V	0.75V
-	DDA_1P8_CSIRX0	1.8V	1.8V
Yes	VDDA_1P8_USB	1.8V	1.8V
Yes	VDDA_3P3_USB	3.3V	3.3V
-	VDD_CORE	0.75V	0.75V
-	VDDR_CORE	0.85V	0.85V
Yes	VDDS_DDR	1.1V	1.1V
Yes	VDDS_OSC0	1.8V	1.8V
Yes	VDDS_DDR_C	1.1V	1.1V
-	VDD_CANUART	3.3V	0.75V
-	VPP	1.8V	NC

In which code, the customer should change to configure above differences?

Thanks and regards,
Koichiro Tashiro

17 days ago

0 Anshu Madwesh 17 days ago

TI__Genius 12590 points

Hi Tashiro-san,

I don't fully understand the query. I would assume that the PMIC or discrete power supply would be driving the required supply voltage, not software/operating system. Can you clarify what you mean?

The voltages listed in SYSCONFIG are likely to ensure the pins are using valid voltage domains .

Best Regards,

Anshu

0 Koichiro Tashiro 16 days ago in reply to Anshu Madwesh

TI__Mastermind 22250 points

Hi Anshu,

Anshu Madwesh said:
I would assume that the PMIC or discrete power supply would be driving the required supply voltage, not software/operating system. Can you clarify what you mean?

The customer just wants to know which codes (or parameters) should be modified in SDK to meet their system voltage requirements.

Anshu Madwesh said:
The voltages listed in SYSCONFIG are likely to ensure the pins are using valid voltage domains .

Do you mean SYSCONFIG does not control PMIC voltage configuration? If so, I understood this point. Thanks!
Please provide where PMIC voltage configuration is done in SDK. The PMIC is same as SK-AM62LP.

Thanks and regards,
Koichiro Tashiro

0 Anshu Madwesh 10 days ago in reply to Koichiro Tashiro

TI__Genius 12590 points

Hi Tashiro-san,

Koichiro Tashiro said:
Do you mean SYSCONFIG does not control PMIC voltage configuration?

Yes, this is correct.

You can see an example of adding the PMIC to the Linux device tree for SK-AM62-LP. This is not required for the PMIC to function, but it allows for a Linux application to utilize the PMIC.

https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm64/boot/dts/ti/k3-am62-lp-sk.dts?h=ti-linux-6.6.y

Best Regards,

Anshu

0 Koichiro Tashiro 8 days ago in reply to Anshu Madwesh

TI__Mastermind 22250 points

Hi Anshu,

The customer found sysconfig generates below code based on "Power Domains" settings.
Below is an example when VDDSHV6 is changed from 1.8V(default) to 3.3V.

How that code is used in SDK?
As I mentioned earlier, he does not use sysconfig to change power rails configuration.
In this case, is it ok just to ignore above code or the same code needs to be added manually?

Thanks and regards,
Koichiro Tashiro

0 Anshu Madwesh 8 days ago in reply to Koichiro Tashiro

TI__Genius 12590 points

Hi Tashiro-san,

Let me loop in the SYSCONFIG expert to comment about the use of that generated code.

To my understanding, this doesn't configure the PMIC.

Thanks,

Anshu

0 PaulM 7 days ago in reply to Anshu Madwesh

TI__Mastermind 26305 points

Tashiro-san,

The untitled.sysconfig file is the file used to save the SysConfig application configuration. It is not used by the Linux or MCU-SDK software.

--Paul

0 Jim Mrowca 7 days ago in reply to PaulM

Expert 2644 points

Paul : doesn't that .sysconfig file can also be created within CCS v20, whether CCS v20 is on Windows or Linux - true? In your response, I think you mean to say "It is not used by any SDK software"

regards

Jim (ex TI-er, '82 - '97)

+1 PaulM 7 days ago in reply to Jim Mrowca

TI__Mastermind 26305 points

Correct, it is not used by any SDK software. It is only used to reload the SysConfig tool state.

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AM625: Power rail configuration in Linux