Altera RapidIO II MegaCore Function - Manual (Page 49)

Chapter 4: Functional Description 4–7
Logical Layer Interfaces
August 2014 Altera Corporation RapidIO II MegaCore Function
User Guide
Logical Layer Interfaces
This section describes the features of the Logical layer module interfaces and how
your system can interact with these interfaces to communicate with a RapidIO link
partner.
The Logical layer consists of the following optional modules:
■ I/O slave and master modules that initiate and terminate NREAD, NWRITE, SWRITE,
and NWRITE_R transactions.
■ Maintenance module that initiates and terminates MAINTENANCE transactions.
■ Doorbell module that transacts RapidIO DOORBELL messages.
■ Avalon-ST pass-through interface for implementing your own custom Logical
layer logic.
In addition, the Logical layer provides an Avalon-MM slave interface called the
Register Access interface which provides access to all of the RapidIO II IP core
registers except the Doorbell Logical layer registers. This interface is present in all
RapidIO II IP core variations.
Figure 4–3 shows a high-level block diagram of the Logical layer with all of the
Logical layer modules.
Register Access Interface
All RapidIO II IP core variations include a Register Access interface. This Avalon-MM
slave interface provides access to all of the registers in the RapidIO II IP core except
the Doorbell Logical layer registers.
Figure 4–3. RapidIO II IP Core Functional Block Diagram
RD = Read port RD = Read port
SRC = Source
SRC = Source
= Dashed lines represent access to register values = Dashed lines represent access to register values
WR = Write port WR = Write port
M = Master port M = Master port
S = Slave port S = Slave port
Legend Legend
Maintenance
M S
I/O Slave Doorbell
S
S
I/O Master
RD/WR RD/WR
SRC
Logical Layer
RapidIO Link
Sink
Maintenance
Master/Slave
Avalon-MM
Register Access
Slave
Avalon-MM
Input/Output
Master
Avalon-MM
Input/Output
Slave
Avalon-MM
Doorbell
Message
Avalon-MM
Avalon-ST
Pass-Through
Transport layer
Physical layer
Registers
Error Management
Extension Block