
8. Serial EEPROM Description  
RTL8305SB 
2002/04/09 
53
Rev.1.0
Unused Registers and bits are reserved for future or internal use, and should use the default value. 
Name  
 Reg.bit 
 Description 
Internal 
0.7 
 Internal use only 
Internal 
0.6 
 Internal use only 
Internal 
0.5 
 Internal use only 
Internal 
0.4 
 Internal use only 
Internal 
0.3 
 Internal use only 
Internal 
0.2 
 Internal use only 
Internal 
0.1 
 Internal use only 
NoEEPROM 
0.0 
 No EEPROM: 
 1: EEPROM does not exist. 
 0: EEPROM exist. 
Internal 
1.7 
 Internal use only 
DisLoop 
1.6 
 Disable Loop Detection Function: 
 1: Disable Loop Detection function. 
 0: Enable Loop Detection function. 
Internal 
1.5 
 Internal use only 
Internal 
1.4 
 Internal use only 
EnP4LED 
1.3 
 Enable Port4 LED: 
 1: Drive LED pins of port4. 
 0: Do not drive LED pins of port4 for special application.  
Default 
1 
1 
1 
1 
1 
1 
1 
0
1 
1 
1 
1 
1 
In UTP application, this bit should be 1 to drive the LEDs of port 4. 
 Reserved for original RTL8305S user only. Not used for general applications. 
 Internal use only 
 Device Ethernet MAC ID
 (6 bytes). 
 Example: for MAC ID = 52 54 4c 83 05 b0. 
 Byte4 = 0x52 (Byte 1 of MAC ID). 
 Byte5 = 0x54 (Byte 2 of MAC ID). 
 Byte6 = 0x4c (Byte 3 of MAC ID). 
 Byte7 = 0x83 (Byte 4 of MAC ID). 
 Byte8 = 0x05 (Byte 5 of MAC ID). 
 Byte9 = 0xb0 (Byte 6 of MAC ID). 
 Port 1 VLAN Index: 
 P1VLANIndex[2:0]=001 means port 1 uses the second VLAN (VLAN B). 
Reserved 
Reserved 
Reserved 
Reserved 
Internal 
Reserved 
Internal 
EthernetID 
1.2 
1.1 
1.0 
1 
1 
1 
1 
2.7~2.4 
2.3~2.0 
3.7~3.2 
3.1~3.0 
4~9 
1111 
1 
11 
0x52 
0x54 
0x4c 
0x83 
0x05 
0xb0 
Reserved 
P1VLANIndex[2] 
P1VLANIndex[1] 
P1VLANIndex[0]
Reserved 
P0VLANIndex[2] 
P0VLANIndex[1] 
P0VLANIndex[0] 
10.7 
10.6 
10.5 
10.4 
10.3 
10.2 
10.1 
10.0 
1 
001 
 Port 0 VLAN Index: 
 P0VLANIndex[2:0] are used to assign the VLAN of port 0. For example, 
P0VLANIndex[2:0]=000 means port 0 use the first VLAN (VLAN A).  
1 
 P0VLANIndex[0] is bit0, P0VLANIndex[1] is bit1, P0VLANIndex[2] is bit2. 
 Port 3 VLAN Index: 
 P3VLANIndex[2:0]=011 means port 3 use the forth VLAN (VLAN D). 
000 
Reserved 
P3VLANIndex[2] 
P3VLANIndex[1] 
P3VLANIndex[0] 
Cont…
11.7 
11.6 
11.5 
11.4 
1 
011