Altera CPRI IP Core - Manual (Page 72)

4–40 Chapter 4: Functional Description
Media Independent Interface to an External Ethernet Block
CPRI MegaCore Function December 2013 Altera Corporation
User Guide
The MII receiver module transmits the K nibble and then the data to the cpri_mii_rxd
output data bus and asserts the cpri_mii_rxdv signal to indicate that the data
currently on cpri_mii_rxd is valid. It sends the K nibble and the data to the
cpri_mii_rxd output data bus on the rising edge of the cpri_mii_rxclk clock. During
the first cpri_mii_rxclk cycle of every new data value on cpri_mii_rxd , the MII
receiver module asserts the cpri_mii_rxwr signal. After the MII receiver module
completes sending data to the external Ethernet block, it deasserts the cpri_mii_rxdv
signal.
While frame synchronization is not achieved, the cpri_mii_rxer signal remains
asserted and cpri_mii_rxdv remains deasserted.
Figure 4–23 illustrates the MII receiver protocol.
Figure 4–23. CPRI MII Receiver Example
cpri_mii_rxclk
cpri_mii_rxwr
cpri_mii_rxdv
cpri_mii_rxd[3:0]
reset
cpri_mii_rxer
D0 D1 K D2 D3 D4 D5 D6 D7
Frame Synchronization
Achieved