KS8995X Micrel Inc, KS8995X Datasheet - Page 26
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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
KS8995X
The KS8995X can classify tagged packets using the 802.1p tag based priority. In this prioritization scheme, the user can enable
the 802.1p classification on a per port basis in bit 5 of registers 0x10, 0x20, 0x30, 0x40 and 0x50 for ports 1, 2, 3, 4, and 5,
respectively. Then the user specifies the 802.1p base priority in register 0x02, bits [6-4]. When a tagged packet is received,
the KS8995X examines the 3 bit 802.1p priority field shown in Figure 8. These 3 bits are compared against the base priority.
The prioritization policy is as follows:
In order to support QoS from end-to-end in a network, the KS8995X can also classify packets based on the IPv4 DiffServ field
shown in Figure 9.
The DiffServ field consists of 6 bits, which can be used to specify 64 code points. The KS8995X provides 64 bits (DSCP[63:0])
in 8 registers (0x60 to 0x67), in which the user specifies the priority of each of the 64 code points. The DiffServ classification
is enabled on a per port basis in bit 6 of registers 0x10, 0x20, 0x30, 0x40 and 0x50 for ports 1, 2, 3, 4, and 5, respectively. If
the DiffServ classification is enabled on a port, the KS8995X will decode the IPv4 DiffServ field and look at the user defined
code point bit to determine if the packet is high priority or low priority. If the code point is a ‘1’, the packet is high priority. If the
code point is ‘0’, the packet is low priority.
M9999-120403
Comparison
802.1p Priority
802.1p Priority < Base Priority
Bytes
Bytes
Base Priority
Preamble
Preamble
8
8
Bits
Tagged Packet Type
(8100 for Ethernet)
DA
DA
6
6
Bits
16
Figure 8. 802.3 Tagged Packet
SA
SA
6
6
Table 4. 802.1p Priority
Low
Priority
High
Figure 9. IPv4 Packet
IP
0x4
802.1p
V
4
Tag
er.
TCI
4
3
4
Length
26
1
Type
2
2
He
Siz
4
ader
LLC
VLAN ID
2
e
6
12
DiffServ
Data
2
46-1500
46-1500
Data
Res.
CRC
CRC
4
4
December 2003
Micrel