Cyclone® V Hard Processor System Technical Reference Manual

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

26.3.2. Message Interface Registers

There are two sets of message interface registers, IF1 and IF2, that provide a means for a host processor or DMA controller to access any message object indirectly. Message objects are transferred between the message RAM and the message buffer registers as a single, atomic operation maintaining data consistency across the message.

Table 215.  Message Interface Register SetThis table lists the structure of each message interface register set, where x represents either set 1 or set 2.

Register Type

Register

Name

Description

Command

IFxCMR

IFx command register

Specifies the transfer direction and selects the portions of the message object to transfer

Message buffer

IFxMSK

IFx mask register

Provides access to the Msk, MDir, and MXtd mask fields of the message object

IFxARB

IFx arbitration register

Provides access to the ID, Dir, Xtd, and MsgVal arbitration fields of the message object

IFxMCTR

IFx message control register

Provides access to the DLC, EoB, TxRqst, RmtEn, RxIE, TxIE, UMask, IntPnd, MsgLst, and NewDat fields of the message object

IFxDA

IFx data A register

Provides access to data bytes 0-3 of the message object

IFxDB

IFx data B register

Provides access to data bytes 4-7 of the message object