How is the optimal DMA burst length determined?

Generally a setting of 16 bursts will be an adequate setting for both 16-bit and 32-bit interfaces. 16-bit interfaces should use burst length of 16 or higher. Burst size could then be increased or decreased to best fit application requirements. It is important that burst requests [DREQ/ assert] are to be serviced immediately in order to avoid FIFO over- or underflows.

Burst length of 512 for 32-bit interfaces and burst length of 1024 for 16-bit interfaces are not recommended.