Peripheral-to-memory transfer in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start the peripheral-to-memory DMA transfer.

Embedded C

DMA_Start_Transfer([1]);

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ADMA_CHANNEL_1

BTIMER2

CADC1

DUART1

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the peripheral name instead of the DMA channel.

Using a timer channel instead of DMA channel.

DMA_Start_Transfer requires the DMA channel identifier to start the transfer.

2fill in blank

medium

Complete the code to configure the DMA data size for peripheral-to-memory transfer.

Embedded C

DMA_Config.DataSize = [1];

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ADMA_DATA_SIZE_64BIT

BDMA_DATA_SIZE_8BIT

CDMA_DATA_SIZE_32BIT

DDMA_DATA_SIZE_16BIT

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 8-bit size when peripheral sends 16-bit data.

Selecting unsupported 64-bit size.

Peripheral data size is often 16 bits for many sensors and peripherals.

3fill in blank

hard

Fix the error in the DMA transfer complete interrupt handler to clear the interrupt flag.

Embedded C

void DMA_IRQHandler(void) {
    if (DMA_GetFlagStatus([1])) {
        DMA_ClearFlag([1]);
        // Process data
    }
}

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ADMA_FLAG_TE1

BDMA_FLAG_HT1

CDMA_FLAG_TC1

DDMA_FLAG_GL1

Attempts:

3 left

💡 Hint

Common Mistakes

Clearing half-transfer flag instead of transfer complete.

Not clearing any flag causing interrupt to repeat.

DMA_FLAG_TC1 indicates transfer complete and must be cleared to avoid repeated interrupts.

4fill in blank

hard

Fill both blanks to set the peripheral and memory addresses for DMA transfer.

Embedded C

DMA_Config.PeripheralBaseAddr = [1];
DMA_Config.MemoryBaseAddr = [2];

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A(uint32_t)&UART1->DR

B(uint32_t)&ADC1->DR

C(uint32_t)buffer

D(uint32_t)data_array

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping peripheral and memory addresses.

Using ADC1 address when UART1 is the peripheral.

Peripheral address is UART1 data register; memory address is the buffer to store data.

5fill in blank

hard

Fill all three blanks to configure DMA transfer direction, enable circular mode, and set priority.

Embedded C

DMA_Config.Direction = [1];
DMA_Config.Mode = [2];
DMA_Config.Priority = [3];

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ADMA_DIR_PeripheralSRC

BDMA_DIR_PeripheralDST

CDMA_MODE_Circular

DDMA_PRIORITY_High

Attempts:

3 left

💡 Hint

Common Mistakes

Setting direction as peripheral destination.

Using normal mode instead of circular for continuous transfer.

Setting low priority causing delays.

Direction is peripheral source for peripheral-to-memory, circular mode allows continuous transfer, and high priority ensures timely DMA service.