Altera cyclone V Technical Reference page 1374

cv_5v4
2016.10.28
Bit
16
etv
15:0
vl
Version
The Version registers identifies the version of the EMAC. This register contains two bytes: one specified by
Synopsys to identify the core release number, and the other specified by Altera.
Bit
15:8
7:0
Debug
The Debug register gives the status of all main blocks of the transmit and receive data-paths and the
FIFOs. An all-zero status indicates that the MAC is in idle state (and FIFOs are empty) and no activity is
going on in the data-paths.
Ethernet Media Access Controller
Send Feedback
Name
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 frame. Similarly, when enabled, only 12
bits of the VLAN tag in the received frame 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 frame are used for comparison and VLAN
hash filtering.
Value
0x0
0x1
This field contains the 802.1Q VLAN tag to identify
the VLAN frames and is compared to the 15th and
16th bytes of the frames being received for VLAN
frames. 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 tag's VLAN Identifier (VID)
field When the ETV bit is set, only the VID
(Bits[11:0]) is used for comparison. If VL (VL[11:0] if
ETV is set) is all zeros, the MAC does not check the
fifteenth and 16th bytes for VLAN tag comparison,
and declares all frames with a Type field value of
0x8100 or 0x88a8 as VLAN frames.
Name
userver
snpsver
Description
Description
Disable 12-Bit VLAN Tag Compare
Enable 12-Bit VLAN Tag Compare
Description
Altera-defined Version
Synopsys-defined Version
(3.7)
Version
Access
RW
RW
Access
RO 0x10
RO 0x37
Altera Corporation
17-159
Reset
0x0
0x0
Reset