SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
The Ethernet module supports the Address Recognition Protocol (ARP) Offload for IPv4 packets. This feature allows the processing of the IPv4 ARP request packet in the receive path and generating corresponding ARP response packet in the transmit path. Ethernet module generates the ARP reply packets for appropriate ARP request packets. The ARP packet for IPv4 is L2 layer packet with Length/Type of 0x0806.
The ARP offloading process is as follows:
The MAC processes only one ARP request at a time. The MAC does not store the fields of multiple ARP requests. If the MAC receives an ARP request when the MAC is already processing an earlier ARP request, the MAC does not generate the ARP reply for new ARP request. The MAC forwards the new ARP request packet to application with ARP Reply Not Generated (Bit 34) status bit set. However, in power-down mode, if the MAC receives an ARP request when the MAC is already processing an earlier ARP request, the MAC drops the new ARP request.
If the Disable CRC check bit of the MAC Extension Configuration bit is set, then the MAC does not check for valid CRC of a ARP request Packet. The MAC can generate an ARP response packet if the other conditions are valid.
The ARP request Packet must always have a valid CRC.