2022-02-08 02:00 AM
Hi,
I'm building a project using Cube MX (LL drivers) for the STM32U575ZITxQ processor (has SMPS) and I would like to get the processor into LL_PWR_REGU_VOLTAGE_SCALE4. Setting the MSIS to 16MHz achieves this but when I add in the 4 bit SDMMC interface in Cube MX the auto generated code only sets the regulator voltage to LL_PWR_REGU_VOLTAGE_SCALE3. This results in higher power consumption.
I am aware of the clock limitations of the SDMMC vs AHB bus and have adjusted PLL1P (sources SDMMC clock) to 16 MHz.
If I manually change the code to set it to SCALE 4 every thing seems to work ok but I would rather not deviate from the auto generated Cube MX code. Is it possible to achieve voltage scale 4 with SDMMC?
Many thanks
Ben
Solved! Go to Solution.
2022-02-09 04:49 AM
Hello @BSmit.7 ,
Actually this is a normal behavior, Range 4 is not allowed when using PLLs, HSI48 not divided by 2 or MSKI/MSIS having 48 MHz.
SDMMC uses either PLL1P or CLK48 as a source clock. In this case, Range 4 can be selected, when SDMMC uses CLK48 and CLK48 Clock Mux is set to MSIK.
PS: Adjust the frequencies according to your application and please make sure to enable LSE as it is required by the MSIK to calibrate itself.
I Hope this helps
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Sara.
2022-02-09 12:25 AM
Hello @BSmit.7 ,
Thanks for your feedback,
Could you please share your ioc file and specify the CubeMX version ?
Thanks,
Sara.
2022-02-09 01:10 AM
Hi Sara,
Thanks for looking into this; Cube MX version 6.4.0.
The attached ioc file has:
Generating the code as-is for the ioc file will put the processor into LL_PWR_REGU_VOLTAGE_SCALE4 - line 124 of main.c for me.
If you enable the SDMMC1 in 4 bit mode this changes to LL_PWR_REGU_VOLTAGE_SCALE3
Many thanks
Ben
2022-02-09 04:49 AM
Hello @BSmit.7 ,
Actually this is a normal behavior, Range 4 is not allowed when using PLLs, HSI48 not divided by 2 or MSKI/MSIS having 48 MHz.
SDMMC uses either PLL1P or CLK48 as a source clock. In this case, Range 4 can be selected, when SDMMC uses CLK48 and CLK48 Clock Mux is set to MSIK.
PS: Adjust the frequencies according to your application and please make sure to enable LSE as it is required by the MSIK to calibrate itself.
I Hope this helps
If your issue is solved, please close this post by clicking the "Select as Best" button. This will help other members of the community find this response more quickly
Sara.
2022-02-09 07:11 AM
Thanks Sara, that has sorted it!
Ben