KS8993 Micrel Inc, KS8993 Datasheet - Page 17

• Manufacturer Part Number: KS8993
• Description: IC SWITCH 10/100 3PORT 128PQFP
• Manufacturer: Micrel Inc

Specifications of KS8993

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Number Of Primary Switch Ports: 3
• Internal Memory Buffer Size: 64
• Operating Supply Voltage (typ): 2.5/3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII/SNI
• 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 Supply Voltage (max): 2.75/3.6V
• Operating Supply Voltage (min): 2.35V
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: 576-1011 - BOARD EVAL EXPERIMENT FOR KS8993
• Lead Free Status / RoHS Status: Not Compliant, Contains lead / RoHS non-compliant

squelch circuit rejects signals with levels less than 400mV or with short pulse widths in order to prevent noises at the RXP or
RXM input from falsely triggering the decoder. When the input exceeds the squelch limit, the PLL locks onto the incoming signal
and the KS8993 decodes a data frame. The receiver clock is maintained active during idle periods in between data reception.
Power Management
Power Save Mode
The KS8993 will turn off everything except for the Energy Detect and PLL circuits when the cable is not installed on an individual
port basis. In other words, the KS8993 will shutdown most of the internal circuits to save power if there is no link.
An additional features are available:
See
LED Mode Selection
Use the following table as a quick reference for setting the LED mode. See MODESEL
MODESEL[3:2] usage.
Auto-Negotiation
The KS8993 conforms to the auto-negotiation protocol as described by the 802.3 committee. Auto-negotiation allows UTP
(Unshielded Twisted Pair) link partners to select the best common mode of operation. In auto-negotiation the link partners
advertise capabilities across the link to each other. If auto-negotiation is not supported or the link partner to the KS8993 is forced
to bypass auto-negotiation, then the mode is set by observing the signal at the receiver. This is known as parallel mode because
while the transmitter is sending auto-negotiation advertisements, the receiver is listening for advertisements or a fixed signal
protocol.
The flow for the link set up is depicted below.
May 2005
KS8993
MODESEL[1:0]
00
01
10
11
“I/O Description”
Transmit Disable for Port 1 set external pin MUX[1] = 1 and MUX[2] = Float
Transmit Disable for Port 2 set external pin MUX[1] = 0 and MUX[2] = Float
Power Down on Port 3 set external pin MUX[1] = float and MUX[2] = 1
LED[1:3]3
Link + Act
RX Act
100 / Link / Act
Link + Act
section for pin description.
Yes
LED[1:3]2
Collision
TX Act
10 / Link / Act
FDX + Collision
Table 1. LED Mode Selection
Figure 2. Auto-Negotiation
No
17
Yes
LED[1:3]1
FDX
FDX
FDX
Reserved
LED[1:3]0
Speed
Reserved
Collision
Speed
No
“I/O Description”
section for
KS8993
Micrel