Cyclone® V Hard Processor System Technical Reference Manual

ID 683126
Date 8/28/2023
Public
Document Table of Contents

26.4.3. Message Object Reconfiguration for Frame Reception

To configure a message object to receive data frames, set the Dir field to 0.

To configure a message object to receive remote frames, set the Dir field to 1, set UMask to 1, and set RmtEn to 0.

To avoid modifying an object while it is being transmitted, you must set MsgVal to 0 before changing any of the following configuration and control bits:

  • ID[28:0]
  • Xtd
  • DLC[3:0]
  • RxIE
  • TxIE
  • RmtEn
  • EoB
  • UMask
  • Msk[28:0]
  • MXtd
  • MDir

The following fields of a message object can be changed without clearing MsgVal:

  • Data0[7:0] to Data7[7:0]
  • TxRqst
  • NewDat
  • MsgLst
  • IntPnd