Question
LTDC prevents CPU (of MCU) from going into sleep mode
LTDC prevents CPU (of my MCU) from going into sleep mode. When i deactivate the LTDC clock, the CPU goes to sleep mode. LTDC interrupt is enabled trough IOC, without enabling of LTDC interrupt, screen remains black. I use the following MCU: STM32L4P5ZGT6P, IDE: STM32CubeIDE 1.11.2. Does someone know why this happens?
An extract of my code:
/* Clock of used hardwares on MCU is deactivated.
*/
__HAL_RCC_DMA1_CLK_DISABLE();
__HAL_RCC_I2C1_CLK_DISABLE();
__HAL_RCC_OSPI2_CLK_DISABLE();
__HAL_RCC_TIM6_CLK_DISABLE();
__HAL_RCC_TIM2_CLK_DISABLE();
__HAL_RCC_TIM3_CLK_DISABLE();
__HAL_RCC_USART2_CLK_DISABLE();
__HAL_RCC_UART4_CLK_DISABLE();
__HAL_RCC_UART5_CLK_DISABLE();
/*Suspend Tick increment to prevent wakeup by Systick interrupt.
Otherwise the Systick interrupt will wake up the device within 1ms (HAL time base)*/
HAL_SuspendTick();
//CPU shall enter sleep mode after this instruction
HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFE);
HAL_ResumeTick();
//Once HAL_ResumeTick() is called, the SysTick interrupt will be enabled and so Tick increment is resumed.
__HAL_RCC_DMA1_CLK_ENABLE();
__HAL_RCC_I2C1_CLK_ENABLE();
__HAL_RCC_OSPI2_CLK_ENABLE();
__HAL_RCC_TIM6_CLK_ENABLE();
__HAL_RCC_TIM2_CLK_ENABLE();
__HAL_RCC_TIM3_CLK_ENABLE();
__HAL_RCC_USART2_CLK_ENABLE();
__HAL_RCC_UART4_CLK_ENABLE();
__HAL_RCC_UART5_CLK_ENABLE();
HAL_Delay(500);
printf("CPU has woke up. Clk = %ld \r\n", HAL_RCC_GetHCLKFreq());