CM4 core doesn't awake after an _SEV on stm32h747

[TreMa]

Hi,

I'm working on a STM32h747 dual core and I'm trying to put the CM4 to sleep so that it wakes up only on a CM7 event.

I used _WFE on CM4 and _SEV on CM7 but the CM4 is never wake up. I release a HSEM directly after WFE in CM4 to notify the CM7 that the CM4 is awake and I never receive it. I tested the HSEM mechanism without putting the CM4 to sleep and it works well.

Here the sleep procedure for the CM4 :

// Disable SEVONPEND => this bit define all pending interrupt (even disabled) as event
 CLEAR_BIT(SCB->SCR, ((uint32_t)SCB_SCR_SEVONPEND_Msk));
 // Disable all interrups
 __disable_irq();
 // Enter in stop mode
 /* Select the regulator state in STOP mode */
 MODIFY_REG (PWR->CR1, PWR_CR1_LPDS, PWR_MAINREGULATOR_ON);
 /* Set SLEEPDEEP bit of Cortex System Control Register */
 SET_BIT (SCB->SCR, SCB_SCR_SLEEPDEEP_Msk);
 /* Ensure that all instructions are done before entering STOP mode */
 __DSB ();
 __ISB ();


 //Generate an event to clean pending events
 __SEV();
 __WFE(); // Consume manual event
 //Sleep
 __WFE ();

On CM7 side I only use __SEV when I want to wake up the CM4.

Where I did wrong ?