The MAC Tx features are as follows:
- Preamble and start-of-packet data (SFD) insertion
- Separate 32-bit status for each packet transmitted from the application
- Automatic CRC and pad generation controllable on a per-packet basis
- Programmable packet length to support Standard or Jumbo Ethernet packets up to 16KB in size
- Programmable Inter Packet Gap (40–96 bit times in steps of 8)
- IEEE 802.3x Flow Control automatic transmission of zero-quanta Pause packet when flow control input transitions from assertion to deassertion (in full-duplex mode)
- Source Address field insertion or replacement, and VLAN insertion, replacement, and deletion in transmitted packets with per-packet or static-global control
- Insertion, replacement, or deletion of up to two VLAN tags
- Insert, replace, or delete queue/channel-based VLAN tags