KS8842-16MQL Micrel Inc, KS8842-16MQL Datasheet - Page 121
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KS8842-16MQL
Manufacturer Part Number
KS8842-16MQL
Description
IC SWITCH 10/100 16BIT 128PQFP
Manufacturer
Micrel Inc
Specifications of KS8842-16MQL
Applications
*
Mounting Type
Surface Mount
Package / Case
128-MQFP, 128-PQFP
Number Of Primary Switch Ports
2
Internal Memory Buffer Size
32
Operating Supply Voltage (typ)
3.3V
Fiber Support
Yes
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 Supply Voltage (max)
3.5V
Operating Supply Voltage (min)
3.1V
Operating Temperature Classification
Commercial
Data Rate
100Mbps
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
For Use With
KS8842-PMQL-EVAL - EVAL KIT EXPERIMENTAL KS8842KS8842-16MQL-EVAL - EVAL KIT EXPERIMENTAL KS8842
Lead Free Status / RoHS Status
Not Compliant, Lead free / RoHS Compliant
Other names
576-1458
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
VLAN Table
The KSZ8842M uses the VLAN table to perform look-ups. If 802.1Q VLAN mode is enabled (SGCR2[15]), this table will
be used to retrieve the VLAN information that is associated with the ingress packet. This information includes FID (filter
ID), VID (VLAN ID), and VLAN membership as described in Table 20:
If 802.1Q VLAN mode is enabled, then KSZ8842M will assign a VID to every ingress packet. If the packet is untagged or
tagged with a null VID, then the packet is assigned with the default port VID of the ingress port. If the packet is tagged
with non null VID, then VID in the tag will be used. The look up process will start from the VLAN table look up. If the VID
is not valid, then packet will be dropped and no address learning will take place. If the VID is valid, then FID is retrieved.
The FID+DA and FID+SA lookups are performed. The FID+DA look up determines the forwarding ports. If FID+DA fails,
then the packet will be broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails, then the
FID+SA will be learned.
VLAN Table Lookup Examples:
Micrel, Inc.
Bit
19
18-16
15-12
11-0
October 2007
1. VLAN Table Read (read the third entry, at the indirect address offset 0x02)
Then
2. VLAN Table Write (write the seventh entry, at the indirect address offset 0x06)
Default Value
1
111
0x0
0x001
Write to reg. IACR with 0x1402 (set indirect address and trigger a read VLAN table operation)
Read reg. IADR5 (VLAN table bits 19-16)
Read reg. IADR4 (VLAN table bits 15-0)
Write to reg. IADR5 (VLAN table bits 19-16)
Write to reg. IADR4 (VLAN table bits 15-0)
Write to reg. IACR with 0x1406 (set indirect address and trigger a read VLAN table operation)
R/W
RW
R/W
R/W
R/W
Description
Valid
1: specifies that this entry is valid, the look up result will be used
0: specifies that this entry is not valid
Membership
Specifies which ports are members of the VLAN. If a DA look up fails (no match in
both static and dynamic tables), the packet associated with this VLAN will be
forwarded to ports specified in this field. For example: 101 means port 3 and 1 are in
this VLAN.
FID
Specifies the Filter ID. The KSZ8842M supports 16 active VLANs represented by
these four bit fields. The FID is the mapped ID. If 802.1Q VLAN is enabled, the look
up will be based on FID+DA and FID+SA.
VID
Specifies the IEEE 802.1Q 12 bits VLAN ID.
Table 20. VLAN Table Format (16 Entries)
121
KSZ8842-16/32 MQL/MVL/MVLI/MBL
M9999-102207-1.9