Visible to Intel only — GUID: rqo1520950685477
Ixiasoft
Visible to Intel only — GUID: rqo1520950685477
Ixiasoft
2.9.1.2.2. RX Strict SFD Checking
The E-Tile Hard IP for Ethernet Intel FPGA IP RX MAC checks all incoming packets for a correct Start byte (0xFB).
If you turn on Enable strict preamble check in the E-Tile Hard IP for Ethernet Intel FPGA IP parameter editor, the RX MAC requires all RX packets to have an Ethernet standard preamble (0x55_55_55_55_55_55). If you turn on Enable strict SFD check , the RX MAC requires all RX packets to have an Ethernet standard Start Frame Delimiter (0xD5).
Strict checking reduces the incidence of runt packets caused by bit errors on the line. However, do not use strict checking in applications where custom preamble values or SFD values are needed.
Enable Strict SFD Check | 0x50A[4]: Preamble Check | 0x50A[3]: SFD Check | Fields Checked | Behavior if Check Fails |
---|---|---|---|---|
Off | Don't Care | Don't Care | Start byte | IP core does not recognize a malformed Start byte as a Start byte |
On | 0 | 0 | Start byte | |
0 | 1 | Start byte and SFD | IP Core drops the packet | |
1 | 0 | Start byte and preamble | ||
1 | 1 | Start byte and preamble and SFD |