LAN9500 Datasheet, PDF (65/213 Pages) SMSC Corporation – USB 2.0 to 10/100 Ethernet Controller Promiscuous mode

LAN950x
FIGURE 5-13:
ETHERNET FRAME WITH LENGTH FIELD AND SNAP HEADER
{DSAP, SSAP, CTRL, OUI[23:16]}
{OUI[15:0], PID[15:0]}
SS
LN N
F
DST SRC e A A
L3 Packet
C
nP P
S
01
012345
1DWORD
Calculate Checksum
FIGURE 5-14:
ETHERNET FRAME WITH VLAN TAG AND SNAP HEADER
{DSAP, SSAP, CTRL,
OUI[23:16]}
{OUI[15:0], PID[15:0]}
DST
SRC
8
1
0
0
V
I
D
L
e
n
S
N
A
P
0
S
N
A
P
1
L3 Packet
F
C
S
0123456
1DWORD
Calculate Checksum
FIGURE 5-15:
ETHERNET FRAME WITH MULTIPLE VLAN TAGS AND SNAP HEADER
{DSAP, SSAP, CTRL,
OUI[23:16]}
{OUI[15:0], PID[15:0]}
DST
SRC
8
1
0
0
V
I
D
8
1
0
0
V
I
D
L
e
n
S
N
A
P
0
S
N
A
P
1
L3 Packet
F
C
S
01245678
1DWORD
Calculate Checksum
The RXCOE supports a maximum of two VLAN tags. If there are more than two VLAN tags, the VLAN protocol identifier
for the third tag is treated as an Ethernet type field. The checksum calculation will begin immediately after the type field.
 2010 - 2015 Microchip Technology Inc.
DS00001875A-page 65