With a STM32u5 controller I'm trying to reach stop1 while still receiving incoming uart data and putting the data memory with DMA. I use LPUART1 and GPDMA1 with the receiving side configured to receive a interrupt on bus idle (RTO) and the DMA is used in standard request mode. These should work in stop1 when the clocks are enabled. Without going to stop mode the code works. When I go to stop1 mode and receive data I will wake up on a overrun error meaning that (I think) that DMA is not working since it is not getting the bytes from the uart peripheral causing the overflow error to hit.
My initiation code looks like this:
HAL_Init();
init_clock_and_power();
MX_ICACHE_Init();
MX_GPDMA1_Init();
MX_GPIO_Init();
MX_LPUART1_UART_Init();
__HAL_RCC_LPUART1_CLKAM_ENABLE();
__HAL_RCC_LPUART1_CLK_SLEEP_ENABLE();
__HAL_RCC_GPDMA1_CLK_SLEEP_ENABLE();
__HAL_RCC_AHB1_CLK_ENABLE();
UART_WakeUpTypeDef wakeup_config;
wakeup_config.WakeUpEvent = UART_WAKEUP_ON_READDATA_NONEMPTY;
HAL_StatusTypeDef res2 = HAL_UARTEx_StopModeWakeUpSourceConfig(&hlpuart1, wakeup_config);
__HAL_LOCK(&hlpuart1);
ATOMIC_SET_BIT(hlpuart1.Instance->CR1, USART_CR1_UESM);
ATOMIC_SET_BIT(hlpuart1.Instance->CR1, USART_CR1_RTOIE);
ATOMIC_SET_BIT(hlpuart1.Instance->CR1, USART_CR1_IDLEIE);
ATOMIC_SET_BIT(hlpuart1.Instance->CR1, USART_CR1_RE);
ATOMIC_SET_BIT(hlpuart1.Instance->CR1, USART_CR1_UE);
__HAL_UNLOCK(&hlpuart1);
I use the following call for receiving data:
HAL_UARTEx_ReceiveToIdle_DMA(handle->uart, handle->rx_buffer, handle->rx_buffer_size);
Has someone a idea what I'm missing to enable the GPDMA or what is going wrong?
