KS8995X Micrel Inc, KS8995X Datasheet - Page 25
![Special Function IC](/photos/6/81/68152/576-128-pqfp_sml.jpg)
KS8995X
Manufacturer Part Number
KS8995X
Description
Special Function IC
Manufacturer
Micrel Inc
Specifications of KS8995X
Leaded Process Compatible
No
Peak Reflow Compatible (260 C)
No
Applications
*
Mounting Type
Surface Mount
Package / Case
128-MQFP, 128-PQFP
Number Of Primary Switch Ports
5
Internal Memory Buffer Size
64
Operating Supply Voltage (typ)
1.8/2.5/3.3V
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 Temperature Classification
Commercial
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
For Use With
576-1021 - BOARD EVAL EXPERIMENT KS8995X
Lead Free Status / RoHS Status
Not Compliant, Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
KS8995X
Manufacturer:
BROADCOM
Quantity:
2 990
Company:
Part Number:
KS8995XA
Manufacturer:
TOSHIBA
Quantity:
32
Part Number:
KS8995XA
Manufacturer:
KENDIN
Quantity:
20 000
SNI Interface Operation
The SNI (Serial Network Interface) is compatible with some controllers used for network layer protocol processing. This
interface can be directly connected to these types of devices. The signals are divided into two groups, one for transmission
and the other for reception. The signals involved are described in the table below.
This interface is a bit wide data interface and therefore runs at the network bit rate (not encoded). An additional signal on the
transmit side indicates when data is valid. Likewise, the receive side has an indicator that conveys when the data is valid.
For half-duplex operation there is a signal that indicates a collision has occurred during transmission.
Advanced Functionality
QoS Support
The KS8995X is a QoS switch, meaning that is it able to identify selected packets on its ingress ports, prioritize them, and
service the packets according to their priority on the egress ports. In this way, the KS8995X can provide statistically better
service to the high priority packets that are latency sensitive, or require higher bandwidth. The KS8995X supports ingress QoS
classification using three different mechanisms: port-based priority, 802.1p tag-based priority, and DSCP priority for IPv4
packets.
Port-based priority is useful when the user wants to give a device on a given port high priority. For example in Figure 7, port
1 is given high priority because it is connected to an IP phone and port 4 is given lower priority because it is connected to a
computer whose data traffic may be less sensitive to network congestion. Each port on the KS8995X can be set as high or
low priority with an EEPROM. The port priority is set in bit 4 of registers 0x10, 0x20, 0x30, 0x40, 0x50 for ports 1, 2, 3, 4 and
5, respectively. Port-based priority is overridden by the OR’ed result of the 802.1p and DSCP priorities if they are all enabled
at the same time.
December 2003
KS8995X
SNI Signal
TXEN
TXD
TXC
COL
CRS
RXD
RXC
Description
Transmit Enable
Serial Transmit Data
Transmit Clock
Collision Detection
Carrier Sense
Serial Receive Data
Receive Clock
P5[0]=1, Hi/Lo Tx Priority
Queues enabled
High Priority Port
Figure 7. Port-Based Priority
P1[3]=1
Table 3. SNI Signals
IP Phone
P1
Queue
Hi-Pri
25
WAN
P2
8995X
Router
P5
Low
Queue
P3
Lo-Pri
P
P
4[3
rio ty
]=0
ri
P4
P
o
rt
KS8995X Signal
SMTXEN
SMTXD[0]
SMTXC
SCOL
SMRXDV
SMRXD[0]
SMRXC
M9999-120403
Micrel