AM5728: Power management

andre feng

Part Number: AM5728

Hi,

AM5728 need to remove the two DSP, remove the two PRU, retain the 3D accelerator and two ARM, so as to achieve the purpose of reducing power consumption.

Set the DSP and PRU in the device tree to not be enabled. As shown below：

However, power consumption has not decreased.

Is there a way to shut down the DSP and PRU modules? Or other ways to reduce power consumption.

Thank you.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The PM experts have been notified. They will respond here.

0 Pavel Botev over 8 years ago

TI__Guru**** 170625 points

Hi Andre,

Do you use AM572x TI EVM or custom board? Do you use AM572x TI PSDK 4.00.00.04?

You should monitor the below two register values before and after removing the DSP1 core:

PM_DSP1_PWRSTCTRL
PM_DSP1_PWRSTST

Do you have the same value in these two registers before and after removing DSP1?

See also if the below e2e thread will be in help:

e2e.ti.com/.../532489

Regards,
Pavel

0 andre feng over 8 years ago in reply to Pavel Botev

Expert 1060 points

Hi Pavel,

The AM572x version used is 03.00.00.04.

Two registers are the same before and after removing the DSP1 kernel.

PM_DSP1_PWRSTCTRL has a value of 0x003F0000;
PM_DSP1_PWRSTST has a value of 0x00000000;

Follow the values of the method registers in the link as follows：
devmem2 0x4A005400 w 0x3
devmem2 0x4AE06400 w 0x003F0000
devmem2 0x4A005420 w 0x0
devmem2 0x4AE06410 w 0x3

Read back the set register：

CM_DSP1_CLKSTCTRL has a value 0x00000003;
PM_DSP1_PWRSTCTRL has a value of 0x003F0000;
CM_DSP1_DSP1_CLKCTRL has a value 0x00070000;
RM_DSP1_RSTCTRL has a value 0x00000003;

Based on the above situation how to close the DSP module and PRU module.

Regards,
Andre

0 Pavel Botev over 8 years ago in reply to andre feng

TI__Guru**** 170625 points

Hi Andre,

Based on the below registers values, I can state that DSP1 is disabled (powered off)

CM_DSP1_CLKSTCTRL = 0x00000003
CM_DSP1_DSP1_CLKCTRL = 0x00070000

PM_DSP1_PWRSTCTRL = 0x003F0000
PM_DSP1_PWRSTST = 0x00000000

What values you have in these registers by default (without any of your modifications)?

Regards,
Pavel

0 andre feng over 8 years ago in reply to Pavel Botev

Expert 1060 points

Hi Pavel,

By default, the value of the register is the following value, and I just wrote it again with devmem2. The default value is the same as the value I wrote.

CM_DSP1_CLKSTCTRL = 0x00000003
CM_DSP1_DSP1_CLKCTRL = 0x00070000

PM_DSP1_PWRSTCTRL = 0x003F0000
PM_DSP1_PWRSTST = 0x00000000

Our goal is to turn off two DSP and turn off two PRU, thus reducing power consumption.

How do you close two DSP and two PRU ?
How to reduce the power consumption of CPU ?

Regards,
Andre

0 Pavel Botev over 8 years ago in reply to andre feng

TI__Guru**** 170625 points

andre feng said:
By default, the value of the register is the following value, and I just wrote it again with devmem2. The default value is the same as the value I wrote.

CM_DSP1_CLKSTCTRL = 0x00000003
CM_DSP1_DSP1_CLKCTRL = 0x00070000

PM_DSP1_PWRSTCTRL = 0x003F0000
PM_DSP1_PWRSTST = 0x00000000

This means that DSP1 core is disabled by default (power off), and you do not need to disable/close/power off DSP1 one more time.

Please provide me the default values of your other cores that you need to power off (DSP2, PRU)

For DSP2 core:

CM_DSP2_CLKSTCTRL
CM_DSP2_DSP2_CLKCTRL
PM_DSP2_PWRSTCTRL
PM_DSP2_PWRSTST

For PRU1:

CM_L4PER2_PRUSS1_CLKCTRL

For PRU2:

CM_L4PER2_PRUSS2_CLKCTRL

Regarding low power consumption, refer to the below links:

http://processors.wiki.ti.com/index.php/Linux_Core_Power_Management_User's_Guide_%28v4.4%29

0 andre feng over 8 years ago in reply to Pavel Botev

Expert 1060 points

Hi pavel,

The default values for the DSP2 PRU are as follows:

For DSP2 core:
CM_DSP2_CLKSTCTRL = 0x00000003
CM_DSP2_DSP2_CLKCTRL = 0x00070000
PM_DSP2_PWRSTCTRL = 0x003F0000
PM_DSP2_PWRSTST = 0x00000000

For PRU1:
CM_L4PER2_PRUSS1_CLKCTRL = 0x00070000

For PRU2：
CM_L4PER2_PRUSS2_CLKCTRL = 0x00070000

Through the above register DSP PRU has been closed ?

The clock frequency of the MPU is 1000000.

AM5728 powered on cat /sys/devices/virtual/thermal/thermal_zone0/temp The result is 58500.

When the while program is executed, the temperature is 67000.

How to reduce CPU power consumption ?

Regards,
Andre

0 Pavel Botev over 8 years ago in reply to andre feng

TI__Guru**** 170625 points

andre feng said:
The default values for the DSP2 PRU are as follows:

For DSP2 core:
CM_DSP2_CLKSTCTRL = 0x00000003
CM_DSP2_DSP2_CLKCTRL = 0x00070000
PM_DSP2_PWRSTCTRL = 0x003F0000
PM_DSP2_PWRSTST = 0x00000000

For PRU1:
CM_L4PER2_PRUSS1_CLKCTRL = 0x00070000

For PRU2：
CM_L4PER2_PRUSS2_CLKCTRL = 0x00070000

Through the above register DSP PRU has been closed ?

Yes, based on above registers values, DSP2, PRU-ICSS1 and PRU-ICSS2 are disabled and should not generate power consumption.

andre feng said:
The clock frequency of the MPU is 1000000.

What is this? Do you mean 1000000Hz (1MHz)?

andre feng said:
AM5728 powered on cat /sys/devices/virtual/thermal/thermal_zone0/temp The result is 58500.

When the while program is executed, the temperature is 67000.

Regarding temperature handling, refer to the below wiki:

processors.wiki.ti.com/.../AM57x_Thermal_Considerations

andre feng said:
How to reduce CPU power consumption ?

Do you need to reduce CPU (Cortex-A15) power consumption during active mode? Or you need to know how to enter into low power mode?

See also if the below wiki page will be in help:

Processors

Processors forum

AM5728: Power management