Altera RapidIO II MegaCore Function - Manual (Page 74)

4–32 Chapter 4: Functional Description
Logical Layer Interfaces
RapidIO II MegaCore Function August 2014 Altera Corporation
User Guide
Maintenance Module
The Maintenance module is an optional component of the I/O Logical layer. The
Maintenance module processes MAINTENANCE transactions, including the following
transactions:
■ Type 8 – MAINTENANCE read and write requests and responses
■ Type 8 – Port-write packets
The Avalon-MM slave interface allows you to initiate a MAINTENANCE read or write
operation on the RapidIO link. The Avalon-MM slave interface supports the following
Avalon transfers:
■ Single slave write transfer with variable wait-states
■ Pipelined read transfers with variable latency
The data bus on the Maintenance Avalon-MM interface is 32 bits wide.
The Avalon-MM master interface allows you to respond to a MAINTENANCE read or
write operation on the RapidIO link. The Avalon-MM master interface supports the
following Avalon transfers:
■ Single master write transfer
■ Pipelined master read transfers
1
MAINTENANCE read and write operations that target the address range for the
RapidIO II IP core registers do not appear on the Avalon-MM master interface.
Instead, the RapidIO II IP core routes them internally to implement the register read
and write operations.
f Refer to the Avalon Interface Specifications for more information about the supported
transfers.
MAINTENANCE port-write transactions do not appear on the Maintenance Avalon-MM
interface. Refer to “Handling Port-Write Transactions” on page 4–36 .
Figure 4–15. NWRITE Transaction on the Input/Output Avalon-MM Slave Interface
sys_clk
ios_rd_wr_waitrequest
ios_rd_wr_write
ios_rd_wr_address[27:0]
ios_rd_wr_writedata[127:0]
ios_rd_wr_byteenable[15:0]
ios_rd_wr_burstcount[4:0]
00000000 AdrA AdrB
w0 w1 w2 w3 w4 w5
F
02 04