KSZ8997 Micrel Inc, KSZ8997 Datasheet - Page 34

• Manufacturer Part Number: KSZ8997
• Description: 8 Port 10/100 Switch With PHY And Frame Buffers (Lead Free)
• Manufacturer: Micrel Inc

Specifications of KSZ8997

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Fiber Support: No
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII
• Power Supply Type: Analog/Digital
• Package Type: PQFP
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Pin Count: 128
• Mounting: Surface Mount
• Jtag Support: No
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-1043

KS8997
4B/5B Coding
In 100BaseTX and 100BaseFX the data and frame control are encoded in the transmitter (and decoded in the receiver) using
a 4B/5B code. The extra code space is required to encode extra control (frame delineation) points. It is also used to reduce
run length as well as supply sufficient transitions for clock recovery. The table below provides the translation for the 4B/5B
coding.
KS8997
Code Type
Data
Control
Invalid
4B Code
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Not defined
0101
0101
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Not defined
Table 6. 4B/5B Coding
34
5B Code
11110
01001
10100
10101
01010
01011
01110
01111
10010
10011
10110
10111
11010
11011
11100
11101
11111
11000
10001
01101
00111
00100
00000
00001
00010
00011
00101
00110
01000
01100
10000
11001
Value
Data value 0
Data value 1
Data value 2
Data value 3
Data value 4
Data value 5
Data value 6
Data value 7
Data value 8
Data value 9
Data value A
Data value B
Data value C
Data value D
Data value E
Data value F
Idle
Start delimiter part 1
Start delimiter part 2
End delimiter part 1
End delimiter part 2
Transmit error
Invalid code
Invalid code
Invalid code
Invalid code
Invalid code
Invalid code
Invalid code
Invalid code
Invalid code
Invalid code
August 2003
Micrel