Agilex™ 7 Hard Processor System Technical Reference Manual

ID 683567
Date 8/13/2024
Public
Document Table of Contents

17.6.2.6.1. Receive Descriptor Acquisition

The receive Engine always attempts to acquire an extra descriptor in anticipation of an incoming frame. Descriptor acquisition is attempted if any of the following conditions is satisfied: †

  • Bit 1 (Start or Stop Receive) of Register 6 (Operation Mode Register) has been set immediately after being placed in the Run state. †
  • The data buffer of the current descriptor is full before the frame ends for the current transfer. †
  • The controller has completed frame reception, but the current receive descriptor is not yet closed. †
  • The receive process has been suspended because of a host‑owned buffer (RDES0[31] = 0) and a new frame is received. †
  • A Receive poll demand has been issued. †