Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 8/15/2024
Public
Document Table of Contents

16.4.2.5.4. Host Bus Burst Access

The internal DMA controller attempts to issue fixed‑length burst transfers on the master interface if configured using the fixed burst bit (fb) of the bmod register. The maximum burst length is indicated and limited by the programmable burst length (pbl) field of the bmod register. When descriptors are being fetched, the master interface always presents a burst size of four to the interconnect.

The internal DMA controller initiates a data transfer only when sufficient space to accommodate the configured burst is available in the FIFO buffer or the number of bytes to the end of transfer is less than the configured burst‑length. When the DMA master interface is configured for fixed‑length bursts, it transfers data using the most efficient combination of INCR4, INCR8 or INCR16 and SINGLE transactions. If the DMA master interface is not configured for fixed length bursts, it transfers data using INCR (undefined length) and SINGLE transactions.