The VPDMA needs to be programmed through descriptors (a pre-defined structure of eight or four 32-bit words depending on type of descriptors) other than VPDMA Memory Mapped Registers (MMR). Descriptors are of three types:
- Data Transfer Descriptors - A memory structure used to describe a desired memory transaction to or from a client.
- Control Descriptors - A memory structure used to perform a control operation inside the DMA controller
- Configuration Descriptors - A memory structure used to described a setup that should be applied to an processing modules like MMR write, scalar coefficient write etc.