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Graduate II
January 23, 2025
Solved

STM32H5 PSSI RDY pin setup and hold times verification

  • January 23, 2025
  • 2 replies
  • 1247 views

Hi,

STM32H533 datasheet (DS14539 Rev 2) in table 88 says that RDY input setup and hold time are both 0.5ns. From my naive point of view it looks like superb value (RDY have to be stable only +-0.5ns around CLK edge). Isn't that a typo ? (STM32H7 PSSIs hold time is about 5.5ns)

h5.png
Thanks,
Michal Dudka

    This topic has been closed for replies.
    Best answer by mƎALLEm

    Hello,

    After an internal check, all the values of H5 in the datasheet are correct while for H7R/S:

    th(RDY) : the minimum RDY input hold time is 0ns and not 5.5ns.

    New internal ticket for issue follow up on H7RS: 201229.

    Thank your for your valuable contribution.

    2 replies

    Technical Moderator
    January 23, 2025

    Hello,

    I'm checking internally if it's the same timing as STM32H7R/S product.

    Most probably the issue is on "RDY input hold time" timing (need to check).

    From STM32H7S datasheet:

    SofLit_0-1737622809131.png

    mƎALLEmAnswer
    Technical Moderator
    January 23, 2025

    Hello,

    After an internal check, all the values of H5 in the datasheet are correct while for H7R/S:

    th(RDY) : the minimum RDY input hold time is 0ns and not 5.5ns.

    New internal ticket for issue follow up on H7RS: 201229.

    Thank your for your valuable contribution.

    Graduate II
    January 23, 2025

    Great. Is this value verified by measurement? I have preliminary observations from which it seems that RDY signal deasserted during CLK edge (asserted 4.9ns after CLK edge) is interpreted as asserted. But I haven't tested it hard enough to say for sure. In a week or two, I might get back to you with that... unless I find a bug somewhere in my code.

    Technical Moderator
    January 24, 2025

    @Michal Dudka wrote:

    Great. Is this value verified by measurement? 


    The values are provided by characterization:

    SofLit_0-1737705664511.png