Cortex M4 core cannot control some peripherals on default settings of STM32H747I-DISCO board

Stat_headcrabed · ‎2021-04-23

I've just bought a STM32H747I-DISCO board and trying to blink the leds on the board (LED1 to LED4). However, when I assign these leds to CM4 core, they won't light when I use default peripheral settings of this board. CM7 core can do this without problems. Besides, when I disable some peripherals on the board, CM4 become able to control the leds. Why this happens?

Amel NASRI · ‎2021-04-28

Hello,

Welcome to ST Community!

Could you please explain more the following: "when I disable some peripherals on the board, CM4 become able to control the leds."?

Which peripherals?

-Amel

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Stat_headcrabed · ‎2021-04-28

Sorry, I forgot to update the post. After debugging, I found that when using PLL1Q as clock source of SDMMC1 peripheral and assign SDMMC1 to CM4, the chip won't get RCC_CR_PLL1RDY while initializing SDMMC1 and run into error handler, causing the problem that I met. But using PLL2R it would run normally, using PLL1Q with CM7 core won't have any problem either. Is this a hardware bug or just a software bug? Or its just my chip broken?