Cyclone® V Hard Processor System Technical Reference Manual
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.
| 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 |