stm32 /stm32h7rs /STM32H7S /ETH /ETH_MACVTR

VLAN Tag Identifier for Receive Packets This field contains the 802.1Q VLAN tag to identify the VLAN packets. This VLAN tag identifier is compared to the 15th and 16th bytes of the packets being received for VLAN packets. The following list describes the bits of this field: Bits[15:13]: User Priority Bit 12: Canonical Format Indicator (CFI) or Drop Eligible Indicator (DEI) Bits[11:0]: VLAN Identifier (VID) field of VLAN tag When the ETV bit is set, only the VID is used for comparison. If this field ([11:0] if ETV is set) is all zeros, the MAC does not check the 15th and 16th bytes for VLAN tag comparison and declares all packets with Type field value of 0x8100 or 0x88a8 as VLAN packets.

Enable 12-Bit VLAN Tag Comparison When this bit is set, a 12-bit VLAN identifier is used for comparing and filtering instead of the complete 16-bit VLAN tag. Bits[11:0] of VLAN tag are compared with the corresponding field in the received VLAN-tagged packet. Similarly, when enabled, only 12 bits of the VLAN tag in the received packet are used for Hash-based VLAN filtering. When this bit is reset, all 16 bits of the 15th and 16th bytes of the received VLAN packet are used for comparison and VLAN Hash filtering.

VLAN Tag Inverse Match Enable When this bit is set, this bit enables the VLAN Tag inverse matching. The packets without matching VLAN Tag are marked as matched. When reset, this bit enables the VLAN Tag perfect matching. The packets with matched VLAN Tag are marked as matched.

Enable S-VLAN When this bit is set, the MAC transmitter and receiver consider the S-VLAN packets (Type = 0x88A8) as valid VLAN tagged packets.

Enable Receive S-VLAN Match When this bit is set, the MAC receiver enables filtering or matching for S-VLAN (Type = 0x88A8) packets. When this bit is reset, the MAC receiver enables filtering or matching for C-VLAN (Type = 0x8100) packets. The ERIVLT bit determines the VLAN tag position considered for filtering or matching.

Disable VLAN Type Check When this bit is set, the MAC does not check whether the VLAN Tag specified by the ERIVLT bit is of type S-VLAN or C-VLAN. When this bit is reset, the MAC filters or matches the VLAN Tag specified by the ERIVLT bit only when VLAN Tag type is similar to the one specified by the ERSVLM bit.

Enable VLAN Tag Stripping on Receive This field indicates the stripping operation on the outer VLAN Tag in received packet:

0 (B_0x0): Do not strip

1 (B_0x1): Strip if VLAN filter passes

2 (B_0x2): Strip if VLAN filter fails

3 (B_0x3): Always strip

Enable VLAN Tag in Rx status When this bit is set, MAC provides the outer VLAN Tag in the Rx status. When this bit is reset, the MAC does not provide the outer VLAN Tag in Rx status.

VLAN Tag Hash Table Match Enable When this bit is set, the most significant four bits of CRC of VLAN Tag are used to index the content of the ETH_MACVLANHTR register. A value of 1 in the VLAN Hash Table register, corresponding to the index, indicates that the packet matched the VLAN Hash table. When the ETV bit is set, the CRC of the 12-bit VLAN Identifier (VID) is used for comparison. When the ETV bit is reset, the CRC of the 16-bit VLAN tag is used for comparison. When this bit is reset, the VLAN Hash Match operation is not performed.

Enable Double VLAN Processing When this bit is set, the MAC enables processing of up to two VLAN Tags on Tx and Rx (if present). When this bit is reset, the MAC enables processing of up to one VLAN Tag on Tx and Rx (if present).

Enable Inner VLAN Tag When this bit and the EDVLP field are set, the MAC receiver enables operation on the inner VLAN Tag (if present). When this bit is reset, the MAC receiver enables operation on the outer VLAN Tag (if present). The ERSVLM bit determines which VLAN type is enabled for filtering or matching.The ERSVLM bit and DOVLTC bit determines which VLAN type is enabled for filtering.

Enable Inner VLAN Tag Stripping on Receive This field indicates the stripping operation on inner VLAN Tag in received packet:

0 (B_0x0): Do not strip

1 (B_0x1): Strip if VLAN filter passes

2 (B_0x2): Strip if VLAN filter fails

3 (B_0x3): Always strip

Enable Inner VLAN Tag in Rx Status When this bit is set, the MAC provides the inner VLAN Tag in the Rx status. When this bit is reset, the MAC does not provide the inner VLAN Tag in Rx status.