Use case: SMARTCARD RX DMA process

Sequence diagram

SMARTCARD receive DMA process

@startuml participant " Application" as p1 participant "HAL SMARTCARD driver" as p2 participant "DMA" as p3 participant "DMAx_IRQHandler" as p4 == initialization and configuration == == Smartcard HAL Receive DMA == p1->p2: <color: green> HAL_SMARTCARD_Receive_DMA(&hsmartcard, aRxBuffer, DATA_TO_RECEIVE_SIZE) note over p2 #00FF00 Receiving data ongoing end note p2->p3: HAL_DMA_Start_IT() p3-->p2: HAL_OK p2-->p1: HAL_OK p4<-: DMAx complete interrupt p4->p3: HAL_DMA_IRQHandler note over p3 #00FF00 End of receiving data end note p3->p2: XferCpltCallback p2->p1: HAL_SMARTCARD_RxCpltCallback(hsmartcard->rx_xfer_count) @enduml

Code snippet

HAL1

HAL2 

#define DATA_TO_RECEIVE_SIZE  255

SMARTCARD_HandleTypeDef hsmartcard;

uint8_t aRxBuffer[DATA_TO_RECEIVE_SIZE];


/* Ensure that all required peripherals
(USART, GPIO,NVIC,DMA etc.) are configured properly
/*
...
*/

/* Smartcard register Receive complete user callback */
HAL_SMARTCARD_RegisterCallback(&hsmartcard, HAL_SMARTCARD_RX_CB_ID,
                               Smartcard_RxCpltCallback);

/* Start a Smartcard Process in dma mode */
HAL_SMARTCARD_Receive_DMA(&hsmartcard, aRxBuffer,
                             DATA_TO_RECEIVE_SIZE)

#define DATA_TO_RECEIVE_SIZE  255

hal_smartcard_handle_t hsmartcard;

uint8_t aRxBuffer[DATA_TO_RECEIVE_SIZE];


/* Ensure that all required peripherals
  (USART, GPIO,NVIC,DMA etc.) are configured properly
/*
...
*/

/* Smartcard register Receive complete user callback */
HAL_SMARTCARD_RegisterRxCpltCallback(&hsmartcard, Smartcard_RxCpltCallback);


/* Start a Smartcard Process in dma mode */
HAL_SMARTCARD_Receive_DMA(&hsmartcard, aRxBuffer,
                         DATA_TO_RECEIVE_SIZE)

Key changes

  1. HAL2 uses a different DMA start API for peripheral transfers (HAL_DMA_StartPeriphXfer_IT_Opt).

  2. HAL2 provides a dedicated receive-complete callback registration API (HAL_SMARTCARD_RegisterRxCpltCallback).