KSZ8873MLL Micrel Inc, KSZ8873MLL Datasheet - Page 32

• Manufacturer Part Number: KSZ8873MLL
• Description: IC ETHERNET SWITCH 3PORT 64-LQFP
• Manufacturer: Micrel Inc

Specifications of KSZ8873MLL

• Data Rate: 100Mbps
• Controller Type: Ethernet Switch Controller
• Interface: MII
• Voltage - Supply: 1.8V, 2.5V, 3.3V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• No. Of Ports: 3
• Ethernet Type: IEEE 802.3u
• Supply Current: 115mA
• Supply Voltage Range: 2.5V, 3.3V
• Digital Ic Case Style: LQFP
• No. Of Pins: 64
• Svhc: No SVHC (15-Dec-2010)
• Base: RoHS Compliant
• Number Of Primary Switch Ports: 3
• Internal Memory Buffer Size: 32
• Fiber Support: No
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII
• Power Supply Type: Analog/Digital
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Mounting: Surface Mount
• Jtag Support: No
• Operating Supply Voltage (max): 1.89/3.465V
• Operating Temperature Classification: Commercial
• Interface Type: MII, RMII
• Operating Temperature Range: 0°C To +70°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-3459

Micrel, Inc.
SMI register access is the same as the MIIM register access, except for the register access requirements presented in
this section.
Advanced Switch Functions
Bypass Mode
The KSZ8873MLL/FLL/RLL also offer a by-pass mode which enables system-level power saving. When the CPU
(connected to Port 3) enters a power saving mode of power down or sleeping mode, the CPU can control the pin 27
SMTXER3/MII_LINK_3 which can be tied high so that the KSZ8873MLL/FLL/RLL detect this change and automatically
switches to the by-pass mode in which the switch function between Port1 and Port2 is sustained. In the by-pass mode,
the packets with DA to port 3 will be dropped and by pass the internal buffer memory, make the buffer memory more
efficiency for the data transfer between port 1 and port 2. Specially, the power saving get more in energy detect mode with
the by-pass to be used.
IEEE 802.1Q VLAN Support
The KSZ8873MLL/FLL/RLL supports 16 active VLANs out of the 4096 possible VLANs specified in the IEEE 802.1Q
specification. KSZ8873MLL/FLL/RLL provides a 16-entries 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.
Advanced VLAN features, such as “Ingress VLAN filtering” and “Discard Non PVID packets” are also supported by the
KSZ8873MLL/FLL/RLL. These features can be set on a per port basis, and are defined in register 18, 34 and 50 for ports
1, 2 and 3, respectively.
September 2010
Registers are 8 data bits wide.
DA found in
Static MAC
Table?
No
No
Yes
Yes
Yes
Yes
For read operation, data bits [15:8] are read back as 0’s.
For write operation, data bits [15:8] are not defined, and hence can be set to either ‘0’ or ‘1’.
FID+SA found in Dynamic MAC Table?
No
Yes
Use FID flag?
Don’t care
Don’t care
0
1
1
1
Table 10. FID+DA Lookup in VLAN Mode
Table 11. FID+SA Lookup in VLAN Mode
Don’t care
FID match?
Don’t care
Don’t care
No
No
Yes
Action
Learn and add FID+SA to the Dynamic MAC Address Table
Update time stamp
DA+FID
found in
Dynamic
MAC Table?
No
Yes
Don’t care
No
Yes
Don’t care
32
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]
KSZ8873MLL/FLL/RLL
M9999-092309-1.2