Using DMA Config

Target Category: Delfino, F280x, F281X, Piccolo, STM32

The DMA Config lets you configure a Direct Memory Access (DMA) channel. The DMA peripheral will automatically transfer memory items from a source set of memory locations to a destination set of memory addresses, on the occurrence of an interrupt on the selected trigger source. The memory locations can include peripheral device addresses allowing automatic transfer of peripheral data to memory or memory to peripheral devices. For example, an ADC channel can be automatically sampled and read to a memory buffer, or a memory buffer with a preconfigured waveform can repeatedly written out at a specific rate to a PWM compare register.

 

Burst Size: Specifies the count of data items to be transferred.

Burst Dst Step: Specifies the step size between memory locations in the destination.

Burst Src Step: Specifies the step size between memory locations in the source.

Channel: Specifies the DMA channel number.

Continuous Mode: If you do not activate Continuous Mode, DMA interrupt generation stops after one interrupt.

Data Size: Indicates the size of a single memory element to be transferred.

Init Dst Address: Specifies the initial destination memory location. This uses standard C address syntax. You can also use Texas Instruments names for hardware devices, for example, &CMPA1 specifies the address of the first PWM compare register.

Init Src Address: Specifies the initial memory location. This uses standard C address syntax. You can also use Texas Instruments names for hardware devices, for example, &ADCRESULT0 specifies the address of the first ADC result register.

One Shot: If One Shot is activated, the DMA unit immediately begins the next burst after servicing the previous burst. Otherwise, the DMA unit waits for a peripheral interrupt after the first burst.

Transfer Dst Step: Specifies the step size between memory locations in the destination.

Transfer Size: Specifies the count of bursts to be transferred.

Transfer Src Step: Specifies the step size between memory locations in the source.

Trigger Src: Specifies the interrupt signal that will cause a DMA transfer to occur.

Wrap Dst Size: Specifies the wrap destination initial count. If the wrap count decrements to zero, the current destination address is incremented by the wrap step, and the wrap counter is set to the wrap size.

Wrap Dst Step: Specifies the wrap destination initial count. If the destination wrap count decrements to zero, the current destination address is incremented by the destination wrap step, and the destination wrap counter is set to the destination wrap size.

Wrap Src Size: Specifies the wrap source initial count. If the source wrap count decrements to zero, the current source address is incremented by the source wrap step, and the source wrap counter is set to the source wrap size.

Wrap Src Step: Specifies the wrap step. If the source wrap count decrements to zero, the current source address is incremented by the wrap step, and the wrap counter is set to the wrap size.