Scalable Scatter-Gather DMA Intel® FPGA IP User Guide

ID 823097
Date 7/08/2024
Public

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3.8.2. Data Descriptor

The format of data descriptors vary depending on the following data transfer type:
  • H2D Streaming Transfer
  • D2H Streaming Transfer
  • H2D Memory Transfer
Table below shows description of common fields of Data Descriptor.
Table 13.  Data Descriptor — Field Description
Field Description
DescrIDX

Unique Identifier for each descriptor. This value is updated to Q_EXTRACT_POINTER register when a descriptor data transfer is complete.

Note: First descriptor DESC_IDX value is 1.
Length The number of bytes to transfer per descriptor, up to 32MB for maximum transfer. Only DWORD-aligned transfer is supported.
HostAddress The read/source address for the transfer.
DeviceAddress The write/destination address for the transfer.