RTL8181 Wireless LAN Access Point/Gateway Controller DATA ...

RTL81810 29-13 - Reserved.0 12-0 Buffer_Size This field indicate the receiver buffer size in bytes. Although themaximum buffer size is 8K bytes/buffer, the NIC purges all dataafter 4K bytes if the packet is larger than 4K-byte long.4 31-17 RSEV Reserved.4 16 TAVA Tag Available. When set, the received packet is an IEEE802.1QVLAN TAG (0x8100) available packet.4 15-0 VLAN_TAG If the packet ‘s TAG is 0x8100, TheNIC extracts four bytes from after source ID, sets TAVA bit to1,and moves the TAG value to this field in Rx descriptor.8 31-0 RxBuff Logic Address of receive buffer.Rx Status Descriptor (OWN=0)31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0R ROWN=0EORFSLSFAEMARPAMBARBOVFRESVFOVFWTESRUNTCRCPID1PI IPD F0TAVAUDPFTCPFFrame_Length Offset 0VLAN_TAGOffset 4RX_BUFFER_ADDRESSDummyOffset 8Offset 12Bye Bit# Bit Name DescriptionOffset#0 31 OWN When set, indicates that the descriptor is owned by NIC. Whencleared, indicates that the descriptor is owned by host system. NICclears this bit when NIC has filled up this Rx buffer with a packet orpart of a packet. In this case, OWN=0.0 30 EOR End of Rx descriptor Ring. Set to 1 indicates that this descriptor is thelast descriptor of Rx descriptor ring. Once NIC’s internal receivedescriptor pointer reaches here, it will return to the first descriptor ofRx descriptor ring after this descriptor is used by packet reception.0 29 FS First segment descriptor. When set, indicates that this is the firstdescriptor of a received packet, and this descriptor is pointing to thefirst segment of the packet.0 28 LS Last segment descriptor. When set, indicates that this is the lastdescriptor of a received packet, and this descriptor is pointing to thelast segment of the packet.0 27 FAE Frame Alignment Error. When set, indicates a frame alignment errorhas occurred on the received packet. The FAE packet is able to bereceived only when RCR_AER is set.0 26 MAR Multicast Address packet Received: When set, indicates that amulticast packet is received0 25 PAM Physical Address Matched. When set, indicates that the destinationaddress of this Rx packet matches to the value in NIC ’s ID registers.0 24 BAR Broadcast Address Received. When set, indicates that a broadcastpacket is received. BAR and MAR will not be set simultaneously.29CONFIDENTIAL v1.0