How to start DMA from FPGA-memory to PCIe Domain, once the FPGA has the data ready? How to set the FPGA as the DMA Master?

Hie Martin Lopez, Using the Internal DMA Descriptor allows user to manage read and write DMA operations. The DMA Descriptor Controller includes read and write data movers to perform local memory reads and writes. It supports up to 128 descriptors for read and write DMAs. Host software programs the DMA Descriptor Controller internal registers with the location and size of the descriptor table residing in the PCI Express main memory. The descriptor control logic directs the DMA read logic to copy the entire table to its local FIFOs. Using the External DMA Descriptor Controller provides more flexibility. You can either modify or replace it to meet your system requirements.You may need to modify the DMA Descriptor Controller for the following reasons: • To implement multi-channel operation • To implement the descriptors as a linked list or to implement a custom DMA programming model • To store descriptors in a local memory, instead of system (host-side) memory To interface to the DMA logic included in this variant, the custom DMA descriptor controller must implement the following functions: • It must communicate with the Write Mover and Read Mover to copy the descriptor table to local memory. • The Write Mover and Read Mover must execute the descriptors stored in local memory. • The DMA Avalon-MM write (WrDCM_Master) and read (RdDCM_Master) masters must be able to update status to the TX slave (TXS). Regards, Nathan