Address Filtering and Broadcast Filtering at RX
The Ethernet 10G MAC core supports unicast, multicast, and broadcast filtering for the incoming RX Ethernet frame. When any of these filters is enabled, each incoming RX Ethernet frame is filtered if the destination address does not match the user-configured MAC Source Address.
When the broadcast filtering is enabled, all RX frames with a destination address of 48’hFFFF_FFFF_FFFF are filtered. To enable broadcast filtering, set the Broadcast Filtering option to Enable.
To enable Unicast or Multicast Address
Filtering, you should drive a pseudo-async signal to port
rx_address_filtering_mask. The
rx_address_filtering_mask is a 48-bit-width input that allows you
to apply bit-wise address filtering to the RX frame that originates from the Ethernet
10G PCS. The respective address bit is compared when the bit is asserted to
1, and uncompared when the bit is set to 0. Table 1
detail unicast, multicast, and broadcast filtering operations.
During the address and broadcast filtering operations, any RX Ethernet frame with a
mismatched address is filtered and silently dropped. A dropped RX frame does not appear
at the RX AXI ST64 interface. Hence, you may need to monitor the
cnt_rx_frame_filtered_by_address statistical reporting to track the
filtered (and dropped) RX frames. Figure 1, Figure 2, and
Figure 3
illustrate the broadcast, unicast, and multicast filtering operations together with the
incremental statistic reporting.
| Broadcast Filtering | rx_address_ filtering_mask |
MAC SOURCE ADDRESS | Destination Address1 | Filtered and Dropped / Output at RX AXI ST | Application |
|---|---|---|---|---|---|
| Unicast | |||||
| Don’t Care | 48’hFFFF_ FFFF_FFFF |
48’hAE3A_ 2020_0080 |
48’hAE3A_ 2020_0080 |
Output at RX AXI ST | Unicast |
| Don’t Care | 48’hFFFF_ FFFF_FFFF |
48’hAE3A_ 2020_0080 |
48’h3E3F_ 7A20_0080 |
Filtered & Dropped | Unicast |
| Multicast | |||||
| Don’t Care | 48’hFFFF_ FFFF_0000 |
48’hAE3A_ 2020_0080 |
48’h3E3F_ 7A20_0080 |
Filtered & Dropped | Multicast |
| Don’t Care | 48’h0FF0_ 00FF_FFFF |
48’hAE3A_ 2020_0080 |
48’h3F3E_ 7A20_0080 |
Filtered & Dropped | Multicast |
| Don’t Care | 48’h0FF0_ 00FF_FFFF |
48’hAE3A_ 2020_0080 |
48’h3E3F_ 7A20_0080 |
Output at RX AXI ST | Multicast |
| Don’t Care | 48’h6FFA_ A5FF_FFFF |
48’hAE3A_ 2020_0080 |
48’h3E3F_ 7A20_0080 |
Output at RX AXI ST | Multicast |
| Broadcast | |||||
| ENABLE | Don’t Care | Don’t Care | 48’hFFFF_ FFFF_FFFF |
Filtered & Dropped | Broadcast |
| DISABLE | Don’t Care | Don’t Care | 48’hFFFF_ FFFF_FFFF |
Output at RX AXI ST | - |
| Address Filtering Is Not Enabled | |||||
| DISABLE | 48’h0000_ 0000_0000 |
48’hAE3A_ 2020_0080 |
48’hAE3A_ 2020_0080 |
Output at RX AXI ST | - |
