adm6995 ETC-unknow, adm6995 Datasheet - Page 35

• Manufacturer Part Number: adm6995
• Description: Port 10/100 Mb/s Single Chip Ethiernet Switch Controller
• Manufacturer: ETC-unknow

ADM6995L
ADMtek Inc.
Preamble/SFD
Tag Protocol TD 8100
Bits
13:12 R/W Mapped priority of tag value (TOS) 6.
15:14 R/W Mapped priority of tag value (TOS) 7.
4.3.8 Packet with Priority: Normal packet content
4.3.9 VLAN Packet
Note:
Value 3 ~ 0 are for priority queue Q3~Q0 respectively.
The Weight ratio is Q3 : Q2 : Q1: Q0 = 8 : 4 : 2 : 1.
The default is port-base priority for un-tag packet and non_IP frame.
Ethernet Packet from Layer 2
ADM6995L will check packet byte 12 &13. If byte[12:13]=8100h then this packet is a
VLAN packet
Byte 12~13
Byte 14~15: Tag Control Information TCI
Type Description
Bit[15:13]: User Priority 7~0
Bit 12: Canonical Format Indicator (CFI)
Bit[11~0]: VLAN ID. The ADM6995L will use bit[3:0] as VLAN group.
Destination (6
bytes)
Byte 0~5
Tag Control Information
TCI
Byte14~15
Source (6 bytes) Packet length (2
Byte 6~11
Byte 12~13
Byte 16~17
bytes)
LEN Length
Data (46-1500
bytes)
Byte 14~
Routing Information
Byte 18
CRC (4 bytes)
Register Description
Initial value
0x3h
0x3h
4-5