SMSC LAN9420 - Manual (Page 61)

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
SMSC LAN9420/LAN9420i 61 Revision 1.22 (09-25-08)
DATASHEET
Example frame configurations:
Figure 3.20 Type II Ethernet Frame
Figure 3.21 Ethernet Frame with VLAN Tag
Figure 3.22 Ethernet Frame with Length Field and SNAP Header
DST SRC
p
r
o
t
0 1 2 3
L3 Packet
F
C
S
Calculate Checksum
DST SRC
8
1
0
0
V
I
D
0 1 2 3
t
y
p
e
4
L3 Packet
F
C
S
Calculate Checksum
DST SRC L3 Packet
F
C
S
S
N
A
P
0 S
N
A
P
1
L
e
n
0 1 2
{DSAP, SSAP, CTRL, OUI[23:16]} {OUI[15:0], PID[15:0]}
3 4 5
Calculate Checksum