KSZ8842-16MQL Micrel Inc, KSZ8842-16MQL Datasheet - Page 40

• Manufacturer Part Number: KSZ8842-16MQL
• Description: IC SWITCH 10/100 16BIT 128PQFP
• Manufacturer: Micrel Inc

Specifications of KSZ8842-16MQL

• Data Rate: 100Mbps
• Controller Type: Ethernet Switch Controller
• Interface: PCI
• Voltage - Supply: 3.1 V ~ 3.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• No. Of Ports: 1
• Ethernet Type: IEEE 802.3u
• Supply Current: 122mA
• Supply Voltage Range: 3.1V To 3.5V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: QFP
• No. Of: RoHS Compliant
• 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
• Interface Type: PCI
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1634 - BOARD EVALUATION KSZ8842-16MQL
• Current - Supply: -
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-1478-5

IEEE 802.1Q VLAN Support
The KSZ8842M supports 16 active VLANs out of the 4096 possible VLANs specified in the IEEE 802.1Q specification.
KSZ8842M provides a 16-entry VLAN table, which converts the 12-bits VLAN ID (VID) to the 4-bits Filter ID (FID) for
address lookup. If a non-tagged or null-VID-tagged packet is received, the ingress port default VID is used for lookup. In
VLAN mode, the lookup process starts with VLAN table lookup to determine whether the VID is valid. If the VID is not
valid, the packet is dropped and its address is not learned. If the VID is valid, the FID is retrieved for further lookup. The
FID + Destination Address (FID+DA) are used to determine the destination port. The FID + Source Address (FID+SA) are
used for address learning. (See Tables 10 and 11.)
QoS Priority Support
The KSZ8842M provides Quality of Service (QoS) for applications such as VoIP and video conferencing. Offering four
priority queues per port, the per-port transmit queue can be split into four priority queues: Queue 3 is the highest priority
queue and Queue 0 is the lowest priority queue. Bit 0 of registers P1CR1, P2CR1, and P3CR1 is used to enable split
transmit queues for ports 1, 2, and the host port, respectively.
Port-Based Priority
With port-based priority, each ingress port is individually classified as a high-priority receiving port. All packets received at
the high-priority receiving port are marked as high priority and are sent to the high-priority transmit queue if the
corresponding transmit queue is split. Bit 4 and 3 of registers P1CR1, P2CR1, and P3CR1 is used to enable port-based
priority for ports 1, 2, and the host port, respectively.
802.1p-Based Priority
For 802.1p-based priority, the KSZ8842M examines the ingress (incoming) packets to determine whether they are tagged.
If tagged, the 3-bit priority field in the VLAN tag is retrieved and compared against the “priority mapping” value, as
specified by the register SGCR6. The “priority mapping” value is programmable.
Figure 13 illustrates how the 802.1p priority field is embedded in the 802.1Q VLAN tag.
Micrel Confidential
November 2005
FID+SA found in Dynamic
MAC Table?
No
Yes
DA found in
Static MAC
Table?
No
No
Yes
Yes
Yes
Yes
Use FID flag?
Don’t care
Don’t care
0
1
1
1
Action
Learn and add FID+SA to the Dynamic MAC Address Table
Update time stamp
Table 10. FID+DA Lookup in VLAN Mode
Table 11. FID+SA Lookup in VLAN Mode
FID match?
Don’t care
Don’t care
Don’t care
No
No
Yes
DA+FID found in
Dynamic MAC
Table?
No
Yes
Don’t care
No
Yes
Don’t care
40
Action
Broadcast to the membership ports
defined in the VLAN Table bits [18:16]
Send to the destination port defined in the
Dynamic MAC Address Table bits [53:52]
Send to the destination port(s) defined in
the Static MAC Address Table bits [50:48]
Broadcast to the membership ports
defined in the VLAN Table bits [18:16]
Send to the destination port defined in the
Dynamic MAC Address Table bits [53:52]
Send to the destination port(s) defined in
the Static MAC Address Table bits [50:48]
KSZ8842-16/32 MQL/MVL
Rev. 1.4