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Features depending on Power Supply-Flash memory access

Yevpator
Associate III

Hello,

I​n the datasheet for the STM32F423 , I see at the table 18 "Features depending on Power Supply range". I want to understand what will be the performance of the MCU if I power it with 1.8 V. I don't clearly understand the table. At the column "Max Flash memory access with wait states "I see for 1.8V 100MHz with 6 wait states, but then in the comment below the table I read that thanks to the ART accelerator the wait states mentioned in the table doesn't impact the execution speed as it is zero wait state... So why not just to write 100MHz with 0 WS in the table? What I am missing?

A​lso in the table there is a column "IO operation " and for 1.8V I read " No io compensation " . What does it mean?

B​ottom line, I don't need ADC, DAC or any analog functionality. Can I work @ 1.8V with the same performance like with 3V?

Thanks!​

1 ACCEPTED SOLUTION

Accepted Solutions

>>What I am missing?

The ART actually has to fetch from the memory if has a cache miss?

The underlying memory will take some 70ns to access rather than the 35ns at 3V, and you'll need to program that into the FLASH subsystem.

>>Can I work @ 1.8V with the same performance like with 3V?

The ART masks a lot of the slowness of FLASH when there are consecutive reads or a hit on the cache. I still suspect the system will be measurably slower at 1.8V

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2 REPLIES 2

>>What I am missing?

The ART actually has to fetch from the memory if has a cache miss?

The underlying memory will take some 70ns to access rather than the 35ns at 3V, and you'll need to program that into the FLASH subsystem.

>>Can I work @ 1.8V with the same performance like with 3V?

The ART masks a lot of the slowness of FLASH when there are consecutive reads or a hit on the cache. I still suspect the system will be measurably slower at 1.8V

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

Thank you for the super fast answer!​