Altera RapidIO II MegaCore Function - Manual (Page 80)

4–38 Chapter 4: Functional Description
Logical Layer Interfaces
RapidIO II MegaCore Function August 2014 Altera Corporation
User Guide
mnt_mnt_s_irq on the Register Access interface to alert your system of the port-write
request.
Maintenance Interface Transaction Examples
This section contains examples of communication on the RapidIO II IP core
Maintenance interface.
Table 4–15 lists the examples.
User Sending MAINTENANCE Write Requests
Table 4–16 lists the Maintenance Avalon-MM interface usage example this section
describes.
To write to a register in a remote endpoint using a MAINTENANCE write request, you
must perform the following actions:
1. Set up the registers.
2. Perform a write transfer on the Maintenance Avalon-MM slave interface.
Figure 4–16 shows the behavior of the signals for four write transfers on the
Maintenance Avalon-MM slave interface.
In the first active clock cycle of the example, user logic specifies the active transaction
to be a write request by asserting the mnt_s_write signal while specifying the write
data on the mnt_s_writedata signal and the target address for the write data on the
mnt_s_address
signal. However, the RapidIO II IP core throttles the incoming
transaction by asserting the mnt_s_writerequest signal until it is ready to receive the
Table 4–15. Maintenance Interface Usage Examples
User Operation Device ID Width Payload Size (Bytes)
Send MAINTENANCE write request 8 32
Receive MAINTENANCE write request 8 32
Send MAINTENANCE read request 16 0
Receive MAINTENANCE read response 16 32
Receive MAINTENANCE read request 16 0
Send MAINTENANCE read response 16 32
Table 4–16. Maintenance Interface Usage Example: Sending MAINTENANCE Write Request
User Operation Device ID Width Payload Size (Bytes)
Send MAINTENANCE write request 8 32
Figure 4–16. Write Transfers on the Maintenance Avalon-MM Slave Interface
sys_clk
mnt_s_waitrequest
mnt_s_write
mnt_s_address
mnt_s_writedata
0x4 0x8 0xC 0x10
32’hACACACAC 32’h5C5C5C5C 32’hBEEFBEEF 32’hFACEFACE