Altera RapidIO II MegaCore Function - Manual (Page 75)

Chapter 4: Functional Description 4–33
Logical Layer Interfaces
August 2014 Altera Corporation RapidIO II MegaCore Function
User Guide
Maintenance Interface Transactions
The Maintenance slave module accepts read and write transactions from the
Avalon-MM interconnect, converts them to RapidIO MAINTENANCE request packets,
and sends them to the Transport layer of the RapidIO II IP core, to be sent to the
Physical layer and transmitted on the RapidIO link. The Maintenance slave module
uses the valid MAINTENANCE response packets that it receives on the RapidIO link to
complete the read transactions on the Maintenance slave interface.
The Maintenance master module executes register read and write transactions in
response to MAINTENANCE requests that the RapidIO II IP core receives on the RapidIO
link, and sends the appropriate MAINTENANCE response packets.
For discussion and examples of the conversion between Avalon-MM transactions and
RapidIO MAINTENANCE packets, refer to
“Maintenance Interface Transaction Examples”
on page 4–38 .
Maintenance Interface Signals
Table 4–13 lists the Maintenance Avalon-MM interface slave port signals.
The Maintenance module supports an interrupt line, mnt_mnt_s_irq, on the Register
Access interface. When enabled, the following interrupts assert the mnt_mnt_s_irq
signal:
■ Received port-write
■ Various error conditions, including a MAINTENANCE read request or MAINTENANCE
write request that targets an out-of-bounds address.
For more information about the Maintenance module interrupts, refer to Table 6–39
on page 6–34 and Table 6–40 on page 6–35 .
Table 4–13. Maintenance Avalon-MM Slave Interface Signals
Signal Direction Description
mnt_s_waitrequest Output Maintenance slave wait request.
mnt_s_read Input Maintenance slave read request.
mnt_s_write Input Maintenance slave write request.
mnt_s_address[23:0] Input
Maintenance slave address bus. The address is a word address, not a
byte address.
mnt_s_writedata[31:0] Input Maintenance slave write data bus.
mnt_s_readdata[31:0] Output Maintenance slave read data bus.
mnt_s_readdatavalid Output Maintenance slave read data valid.
mnt_s_readerror Output
Maintenance slave read error, which indicates that the read transfer did
not complete successfully. This signal is valid only when the
mnt_s_readdatavalid
signal is asserted.