VT6516 ETC, VT6516 Datasheet - Page 27

• Manufacturer Part Number: VT6516
• Description: 16/12 PORT 10/1000 ASE T/TX
• Manufacturer: ETC

The address table structure as figure 3-5, The address table entries contains the MAC address information
from bit 11 to bit 47, others bits 0~10 or bits 0~14 (2K~32K) as the address entries hashing index, the total
address entries of device assigned by the HASH_BITS(1400H).
Initialization procedures include to set forwarding address table control in normal mode and to invalidate all
forwarding table entries by setting the age-count field as 0. Configure port mask register (USER_PM) for
broadcast MAC address. Configure port mask and MAC address pairs that allow any static MAC to port
mask mapping.
Forwarding table entry has 96 bits, defined as follows:
bit 18-0
bit 35-19
bit 46-36
bit 50-47
bit 51
Bit 54-52
Bit 57-55
bit 58
bit 64-59
bit 95-65
VIA Technologies, Inc.
95
reserved
95
reserved
65
Frame type Reserved (zero)
Frame tag type Reserved (zero)
VLAN tag flag Reserved (zero)
VLAN ID
Next entry pointer
port mask (bit[16]: CPU port + bit[15:0]: Ethernet ports 0~15)
Packet byte count
Source port ID
Priority
VLAN ID
reserved for future
64
59
tage flag
64
VLAN
58
VLAN ID
63
58
Figure 3-2 Free buffer link structure
57
tag type
Table 1-0 Free buffer link structure
frame
tage flag
Figure 3-5 The Address table entries structure +
-27-
VLAN
55
57
54
priority
52
static/dynamic
frame
type
flag
Preliminary VT6516 Datarsheet
51
56
source
port ID
50 47
55
count
age
packet byte
46
count
54
53
16 ports
+1 cpu
mask
port
36
35 19
16 ports
3736
mask
+1 cpu
port
fixed, even for key
MAC address
length = 11~15
next entry
bit-47:11
18
pointer to
0
0