Altera Interlaken MegaCore Function - Manual (Page 30)

4–4 Chapter 4: Functional Description
Interfaces Overview
Interlaken MegaCore Function June 2012 Altera Corporation
User Guide
If you turn on the Exclude transceiver parameter to generate a faster simulation
model, your functional simulation model’s interface to and from the Interlaken link
transceivers presents the data in slightly different format and exposes different clocks.
In addition, the application or testbench must implement the reset sequence. For more
information, refer to
Appendix B, Excluding Transceivers for Faster Simulation .
Application Interface
The application interface provides two channels of communication to and from the
Interlaken link. Each channel in each direction is implemented as an Avalon-ST
interface with one modification. The width of the Avalon-ST interfaces depends on
the number of lanes in the Interlaken MegaCore function instance.
Depending on the parameter values you set in the Interlaken parameter editor,
additional signals may be available to the application.
Avalon-ST Interface
The Avalon-ST interface provides a standard, flexible, and modular protocol for data
transfers from a source interface to a sink interface. The Avalon-ST interface protocol
allows you to easily connect components to the Interlaken MegaCore function.
The application interface implements an Avalon-ST interface with a modification in
how the empty signal is used and monitored. In the Avalon-ST interface, the empty
signal is monitored only when end-of-packet is asserted. However, the application
interface asserts and monitors this signal during other data-valid clock cycles as well.
This modification allows the application to provide data in incomplete words,
mirroring the same capability on the Interlaken link.
For more information about the application interface, refer to “Arbiter” on page 4–12
and “Packet Regrouper” on page 4–19 .
f For more information about the Avalon-ST interface, refer to Avalon Interface
Specifications .
Optional In-Band Flow Control and Dynamic Configuration Signals
Depending on the parameter values you set in the Interlaken parameter editor, the
application interface may include additional signals that the application controls to
dynamically configure the BurstMax and BurstShort signals, or receives and controls
to manage the in-band flow control bits on the Interlaken link. For more infomation
about BurstMax and BurstShort configuration, refer to
“Interlaken Interface” and to
Table 5–8 on page 5–7 . For more information about the in-band flow control signals,
refer to “Calendar and Status Block” on page 4–20 and to Table 5–6 on page 5–5 and
Table 5–8 on page 5–7 .
Out-of-Band Flow Control Interface
The out-of-band flow control interface conforms to the out-of-band requirements in
Section 5.3.4.2, Out-of-Band Flow Control, of the Interlaken Protocol Definition, Revision
1.2. This interface is included in the Interlaken MegaCore function if you turn on the
Enable out-of-band flow control
parameter.
For more information, refer to “Out-of-Band Flow Control Block” on page 4–24 .