How to Reduce A-core Frequency on i.MX8ULP

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How to Reduce A-core Frequency on i.MX8ULP

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YashParekh
Contributor III

 

I'm working on a project using the i.MX8ULP processor, and I’m trying to reduce the A-core (Cortex-A35) clock frequency to around 40–50 MHz in order to lower the overall power consumption.

Currently, I’m using the following steps to switch the A-core clock source and adjust PLL settings:

 

# Switch A35 to FRO 192 MHz
/unit_tests/memtool -32 0x292c0014=0x08000000

# Disable PLL2
/unit_tests/memtool -32 0x292c0500=0x03000000

# Read division and multiplication factors
/unit_tests/memtool -32 0x292c0014 1
/unit_tests/memtool -32 0x292c0510 1

# Enable PLL2
/unit_tests/memtool -32 0x292c0500=0x03000001

# Switch A35 back to PLL2
/unit_tests/memtool -32 0x292c0014=0x18000000

However,  I need to bring it down to the 40–50 MHz range for this how can i able to achieve this? 

  • Is it possible to run the A35 core at 40–50 MHz on the i.MX8ULP?

  • If so, how should the clock source and dividers be configured to achieve this?

 

 

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Bio_TICFSL
NXP TechSupport
NXP TechSupport

Hello,

I think is not possible with PLL, please check this appnote:

https://www.nxp.com/docs/en/application-note/AN13951.pdf

 

https://docs.nxp.com/bundle/AN14486/page/topics/introduction.html

 

 

Regards

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