Use case: DMA channel peripheral transfer in circular mode

Sequence diagram

Peripheral transfer in circular mode.

@startuml hide footbox participant "User Application" as part1 participant "PPP Driver" as part4 participant "DMA Driver" as part3 participant "NVIC" as part5 group Configuration part1->part3 : HAL_DMA_Init() part1->part3 : HAL_DMAEx_List_Init() end group Process group Start part1->part4 : **Start PPP DMA process** end group Repeated until PPP stop DMA part4->part3 : HAL_DMAEx_List_Start_IT() part5->part3 : HAL_DMA_IRQHandler() part3->part4 : PPP DMA transfer callback part4->part1 : <b>User PPP process callback end part1->part4 : **Stop PPP DMA process** part4->part3 : HAL_DMA_Abort_IT() part3->part4 : HAL_DMA_RegisterCallback(AbortCallback) part4->part1 : User callback() end @enduml

Note

The DMA start and stop procedures must be adjusted according to the selected peripheral (PPP).

Code snippet

The following code snippet is an example of I2C DMA transfer in circular mode.

HAL1

HAL2 

HAL_DMA_Init(&handle_GPDMA1_Channe0);
HAL_DMAEx_List_Init(&handle_GPDMA1_Channe0);

HAL_DMA_Init(&hdma1, GPDMA1_CH0);
HAL_DMA_SetConfigPeriphLinkedListCircularXfer(&hdma1, &DMA_Node_I2C1_TX, &xfer_cfg_i2c1_tx_dma);

Key changes

  1. HAL2 configures circular peripheral transfers using HAL_DMA_SetConfigPeriphLinkedListCircularXfer().

  2. HAL2 starts the peripheral transfer using HAL_DMA_StartPeriphXfer_IT_Opt().

  3. Abort and IRQ handling remain based on HAL_DMA_Abort_IT() and HAL_DMA_IRQHandler().