Update of loop division ratio by SAM E54 Xplained

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I own a SAM E54 Xplained Pro and a custom board.

 

The custom board is battery-powered and is designed to repeat normal operation and sleep.

In order to reduce the current consumption during sleep,

I want to switch the CPU clock between 120MHz for normal operation and 30MHz for sleep, but I cannot change the clock.

 

Please give me advice.

 

For clock switching, refer to this procedure (SAM D5x / E5x Family Data Sheet DS60001507G-page 705).

 

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Hi,

 

in data sheet: 54.13.5 Fractional Digital Phase Lock Loop (FDPLL) Characteristics:

Output Frequency 96 - 200 MHz. So, your 30MHz maybe is too low when changeing ratio on the fly.

Surprise: As soon as one's doing it correctly - it works!

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thank you for the advice.
Consider new measures.

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You can also change the synchronous clock division ratio in the CPUDIV register to change the CPU clock speed on the fly.

 

In the datasheet see:

15.6.2.4 Selecting the Synchronous Clock Division Ratio

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thank yousmiley
When I set the CPUDIV register to Divide by 8, I was able to reduce the current consumption by 3mA with a custom board.