MII Interface Description in CPRI MegaCore Function v10.1 User Guide Contains Errors

The CPRI MegaCore Function v10.1 User Guide contains an erroneous example of MII interface behavior. Figure 4-23, CPRI MII Interface Transmitter Example 1, on page 78 of the CPRI MegaCore Function User Guide shows input behavior that the MII interface cannot handle. Specifically, if the cpri_mii_txen signal toggles during transmission of a single packet, as shown in Figure 4-23, the incoming data is not transmitted correctly on the CPRI link.

You should not rely on Figure 4-23, nor any part of its explanation that describes a toggling cpri_mii_txen input signal. Refer instead to Figure 4-24 on the same page, CPRI MII Interface Transmitter Example 2.

Figure 4-26, CPRI MII Interface Signals on Transmitting RE or REC Master and on Receiving RE Slave, also shows this behavior. Replace Figure 4-26 on page 80 of the CPRI MegaCore Function User Guide with the following figure.

This documentation issue affects all CPRI MegaCore function variations configured with the MII interface.

Data received on the CPRI IP core MII interface is not transmitted correctly on the CPRI link if the data originates at an external Ethernet block that toggles the cpri_mii_txen signal input to the CPRI IP core.

Do not refer to Figure 4-23 in the CPRI MegaCore Function v10.1 User Guide. Instead, refer to Figure 4-24 and its description for correct behavior of an external Ethernet block.

This issue is fixed in version 11.0 of the CPRI MegaCore Function User Guide. The erroneous figure is removed.