Altera 10-Gbps Ethernet MAC MegaCore Function - Manual (Page 70)

Chapter 7: Functional Description 7–3
Interfaces
February 2014 Altera Corporation 10-Gbps Ethernet MAC MegaCore Function User Guide
7.2. Interfaces
The 10GbE MAC IP core offers the following modes:
■ Avalon-ST transmit and receive interface on the client side
■ Avalon-MM control and status register interface
■ SDR XGMII transmit and receive interface on the network side (10GbE MAC)
or
GMII or SDR XGMII transmit and receive interface on the network side (1G/10G
MAC)
or
MII, GMII or SDR XGMII transmit and receive interface on the network side
(10M-10G MAC)
7.2.1. Avalon-ST Interface
The client-side interface of the MAC employs the Avalon-ST protocol, which is a
synchronous point-to-point, unidirectional interface that connects the producer of a
data stream (source) to a consumer of the data (sink). The key properties of this
interface include:
■ Frame transfers marked by startofpacket and endofpacket signals.
■ Signals from source to sink are qualified by the valid signal.
■ Errors marking a current packet are aligned with the end-of-packet cycle.
■ Use of the ready signal by the sink to backpressure the source. The source must
respond to the ready signal from sink by deasserting the valid signal after a fixed
number of cycles defined by the ready latency.
Figure 7–3. 10M-10GbE MAC IP Core Block Diagram
Avalon-MM
Bridge
10M-10GbE MAC
64-bit
Avalon-ST
Receive Interface
Avalon-MM
Configuration
64-bit
Avalon-ST
Transmit Interface
Link
Fault Flow
Control
MAC Tx
MAC Rx
64
64
32
XGMII Transmit
Interface
72
GMII Transmit
Interface
8
MII Transmit
Interface
4
GMII Receive
Interface
8
MII Receive
Interface
4
XGMII Receive
Interface
72