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mete
Senior
November 9, 2023
Solved

choosing flash latency vs. VOS

Giving an example for my question. For STM32H563, for freq. 140MHz, it is possible to use three different configurations:

- 4 WS, VOS2

- 4 WS, VOS1

- 3 WS, VOS0

If I want to optimize for power, I should choose 4WS VOS2. If I want to optimize for performance, I should choose 3WS VOS0. There is no point choosing 4 WS, VOS1. Am I correct in this interpretation ?

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STOne-32
STOne-32Best answer
ST Technical Moderator
November 9, 2023

Dear @mete ,

Yes this is correct , here you go . Voltage scaling is mainly changing the voltage of the internal digital Vcore.  To reach 250MHz , VOS0 is a must . Having a lower Vcore will save a lot of power budget , Power = Current ( constant) * VCore and of course the same in low power modes - static . But will decrease transistors performance for switching .

 

https://www.st.com/content/ccc/resource/training/technical/product_training/group1/43/67/5f/da/da/56/49/54/STM32H5-Memory-FLASH/files/stm32h5-memory-flash.pdf/jcr:content/translations/en.stm32h5-memory-flash.pdf

IMG_5559.jpeg

IMG_5558.jpeg

Hope it helps,

STOne-32

1 reply

STOne-32
STOne-32Best answer
ST Technical Moderator
November 9, 2023

Dear @mete ,

Yes this is correct , here you go . Voltage scaling is mainly changing the voltage of the internal digital Vcore.  To reach 250MHz , VOS0 is a must . Having a lower Vcore will save a lot of power budget , Power = Current ( constant) * VCore and of course the same in low power modes - static . But will decrease transistors performance for switching .

 

https://www.st.com/content/ccc/resource/training/technical/product_training/group1/43/67/5f/da/da/56/49/54/STM32H5-Memory-FLASH/files/stm32h5-memory-flash.pdf/jcr:content/translations/en.stm32h5-memory-flash.pdf

IMG_5559.jpeg

IMG_5558.jpeg

Hope it helps,

STOne-32