Altera RapidIO MegaCore Function - Manual (Page 133)

August 2014 Altera Corporation RapidIO MegaCore Function
User Guide
6. Software Interface
The RapidIO IP core supports the following sets of registers that control the RapidIO
IP core or query its status:
■ Standard RapidIO capability registers—CARs
■ Standard RapidIO command and status registers—CSRs
■ Extended features registers
■ Implementation defined registers
■ Doorbell specific registers
Some of these register sets are supported by specific RapidIO IP core layers only. This
chapter organizes the registers by the layers they support. The Physical layer registers
are described first, followed by the Transport and Logical layers registers.
All of the registers are 32 bits wide and are shown as hexadecimal values. The
registers can be accessed only on a 32-bit (4-byte) basis. The addressing for the
registers therefore increments by units of 4.
1
Reserved fields are labelled in the register tables. These fields are reserved for future
use and your design should not write to or rely on a specific value being found in any
reserved field or bit.
The following sets of registers are accessible through the System Maintenance
Avalon-MM slave interface.
■ CARs—Capability registers
■ CSRs—Command and status registers
■ Extended features registers
■ Implementation defined registers
A remote device can access these registers only by issuing read/write MAINTENANCE
operations destined for the local device. The local device must route these
transactions, if they are addressing these registers, from the Maintenance master
interface to the System Maintenance slave interface. Routing can be done by a Qsys
system or by a user-provided design. Refer to
“Maintenance Module” on page 4–26
for more details.
The doorbell registers can be accessed through the Doorbell Avalon-MM slave
interface. These registers are implemented only if you turn on Doorbell Tx enable or
Doorbell Rx enable
in the RapidIO parameter editor. If you turn on only Doorbell Rx
enable , only the Rx-related doorbell registers are implemented. If you turn on only
Doorbell Tx enable , only the Tx-related doorbell registers are implemented.