adm6996f Infineon Technologies Corporation, adm6996f Datasheet - Page 30

• Manufacturer Part Number: adm6996f
• Description: 6 Port 10/100 Mb/s Single Chip Ethernet Switch Controller
• Manufacturer: Infineon Technologies Corporation

ADM6996F
Infineon-ADMtek Co Ltd.
3.17 Port Locking
3.18 VLAN setting & Tag/Untag & port-base VLAN
Switch connect other device such as another Switch must by two way. First one is Cross
Over TP cable. Second way is use extra RJ45 which crossover internal TX+- and RX+-
signal. By second way customer can use one by one cable to connect two Switch devices.
All these effort need extra cost and not good solution. ADM6996F provide Auto MDIX
function which can adjust TX+- and RX+- at correct pin. User can use one by one cable
between ADM6996F and other device. This function can be Enable/Disable by hardware
pin and EEPROM configuration register 0x01h~0x09h bit 15. If hardware pin set all port
at Auto MDIX mode then EEPROM setting is useless. If hardware pin set all port at non
Auto MDIX mode then EEPROM can set each port this function enable or disable.
Port locking function will provide customer simple way to limit per port user number to
one. If this function is turn on then ADM6996F will lock first MAC address in learning
table. After this MAC address locking will never age out except Reset signal. Another
MAC address which not same as locking one will be dropped. ADM6996F provide one
MAC address per port. This function is per port setting. When turn on Port Locking
function, recommend customer turn off aging function. See EEPROM register 0x12h bit
0~8.
ADM6996F supports bypass mode and untagged port as default setting while the chip is
power-on. Thus, every packet with or without tag will be forwarding to the destination
port without any modification by ADM6996F. Meanwhile port-base VLAN could be
enabled according to the PVID value ( user define 4bits to map 16 groups written at
register 13 to register 22 ) of the configuration content of each port.
ADM6996F also supports 16 802.1Q VLAN groups. In VLAN four bytes tag include
twelve VLAN ID. ADM6996F learn user define four bits of VID. If user need to use this
function, two EEPROM registers are needed to be programmed first :
* Port VID number at EEPROM register 0x01h~0x09h bit 13~10, register 0x28h~0x2bh
and register 0x2ch bit 7~0: ADM6996F will check coming packet. If coming packet is
non VLAN packet then ADM6996F will use PVID as VLAN group reference.
ADM6996F will use packet’s VLAN value when receive tagged packet.
* VLAN Group Mapping Register. EEPROM register 013h~022h define VLAN grouping
value. User use these register to define VLAN group.
User can define each port as Tag port or Untag port by Configuration register Bit 4. The
operation of packet between Tag port and Untag port can explain by follow example:
Example1: Port receives Untag packet and send to Untag port.
VLAN group resister. If destination port same VLAN as receiving port then this packet
will forward to destination port without any change. If destination port not same VLAN
ADM6996F will check the port user define four bits of VLAN ID first then check
Function Description
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