Visible to Intel only — GUID: wdz1697710073826
Ixiasoft
Visible to Intel only — GUID: wdz1697710073826
Ixiasoft
4.3.1.3. Control Source Address, PAD, and CRC Insertion
The i_tx_skip_crc port disables the insertion of CRC on a per packet basis.
Some systems have multiple streams of data feeding the same Ethernet link. If some of those streams provide packets with CRC already calculated, you can use the i_tx_skip_crc signal to prevent them from being recalculated. Some systems use frames that are smaller than the Ethernet minimum size. For these frames, padding must be disabled, though this requires CRC to be calculated in the fabric for those frames.
Some protocols modify the CRC to indicate special conditions. You can use the i_tx_skip_crc signal to pass these special CRCs to the Ethernet Frame without disabling CRC insertion for all frames. Use the i_tx_skip_crc signal when bridging packets and respacing them without changing the received CRC.
Ethernet Frame | i_tx_skip_crc = 0 | i_tx_skip_crc = 1 |
---|---|---|
Source Address | When you enable Use Source Address Insertion, i_txmac_saddr replaces the content of the source address bytes. | Regardless of Use Source Address Insertion status, the source address bytes are not replaced. |
Padding | Frames with size of 64 bytes of less are padded to 64 bytes. | No padding is added. |
CRC (Frame Check Sequence) | Calculates the packet's CRC and append it to the end. | No CRC calculation. Instead, uses last four bytes of the i_tx_data as a CRC value. |