STM32H523R PSSI clock configuration

[Hawaka]

Hello,

I’m trying to setup the PSSI interface on the STM32H523RETx to transmit data. I cannot find how is the PSSI_PDCK configure. Neither in the clock tree nor in the RCC register the PSSI clock can be configured (except for enabling it). In RM0481 table 305 the AHB clock is listed for PSSI_HCLK, but how is PSSI_PDCK generated?

Is it not possible to internally generate the clock? How is the requirement of AHB clock must be at least 2.5x PSSI_PDCK achieved?

In CubeMX (v6.14.1) I also couldn’t find any parameters for the PSSI clock.

Thanks!

[KDJEM.1 · Accepted solution]

Hello @Hawaka and welcome to the community;

You can transmit or receive data only if the PSSI_PDCK is generated by RCC or input on PSSI_PDCK. So, the PSSI_PDCK pin must be connected to a clock source pin like as MCO2 pin, timer pin….

You need to respect that AHB clock frequency must be at least 2.5 times higher than the PSSI_PDCK frequency (clock source connected to  PSSI_PDCK pin)

I hope this answer your request.

Thank you.

Kaouthar

[Hawaka]

Hello,

1. If generated by RCC, what it the frequency and how do you configure it?

2. If the pin PSSI_PDCK receive a clock as input, where do you configure that pin as input?

3. To resume, if I want to transmit data I have to physically give a clock signal on the PSSI_PDCK pin. Is there really no internal clock mux ?

In any case, would be nice to improve the documentation on that topic.

Thanks!

[KDJEM.1]

Hello @Hawaka ;

Thank you for sharing your feedback. I reported internally.

I recommend you to use STM32CubeMXfor PSSI and RCC configuration.

I advise you to look at PSSI examples and How to configure and use the PSSI on the STM32H7 - STMicroelectronics Community article to start with PSSI.

I hope this help you.

Thank you.

Kaouthar