Cyclone® V Hard Processor System Technical Reference Manual

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

26.3.1.2.1. Use Acceptance Mask (UMask)

  • 0= Ignore mask. Msk[28:0], MXtd, and Mdir have no effect on acceptance filtering. For an incoming message to be accepted, all the following conditions must be met:
    • The received message is a data frame with message direction set to 0 (receive) or is a remote frame with message direction set to 1 (transmit).
    • The received message identifier matches the message identifier (ID[28:0]) of the message object.
    • The received identifier extension bit matches the identifier extension bit (Xtd) of the message object.
  • 1= Use mask (Msk[28:0], MXtd, and MDir) for acceptance filtering if the respective mask bits are set up for acceptance filtering. For an incoming message to be accepted, all the following conditions must be met:
    • The received message is a data frame with message direction set to 0 (receive) or is a remote frame with message direction set to 1 (transmit) with the MDir mask bit enabled.
    • The received message identifier matches the message identifier (ID[28:0]) of the message object with the Msk[28:0] mask bits enabled
    • The received identifier extension bit matches the identifier extension bit (Xtd) of the message object, with the MXtd mask bit enabled.
Note: If the UMask bit is set to 1, the message object's mask bits have to be programmed during the initialization of the message object before MsgVal is set to 1.