SWRU626 December 2025 CC3501E , CC3551E
The ADC has a dedicated interface for communicating with the DMA. This interface is useful to offload work from the CPU by using the DMA to store ADC results to memory automatically.
The DMAEN bit in the CTL2 register is used to enable the DMA for ADC data transfer. The DMAEN bit is cleared by ADC hardware when the DMA “DONE" status signal is asserted. Software is expected to re-enable the DMA using DMAEN to arm the ADC to generate the next DMA trigger.
The ADC also incorporates an optional First-In-First-Out buffer to provide a way for ADC results to be stored for future use, such as transferring to memory by the DMA. Either the CPU or the DMA can be used to move data from the ADC regardless of whether the FIFO is enabled or disabled. The memory result flags in the RIS register of the third event publisher serve as the FIFO threshold and can be unmasked to generate the DMA trigger.
The following sections explain the details of using the ADC with DMA or CPU in various conversion modes and with the FIFO enabled or disabled.