KSZ8842 Datasheet, PDF (1/2 Pages) Micrel Semiconductor – 2-Port Ethernet Switch with PCI Interface

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KSZ8842
PMQL/PMQLI
Product Brief
2-Port Ethernet Switch with
PCI Interface
Description
The KSZ8842-PMQL is the industry’s first 2-port switch
with a PCI CPU interface. An Industrial Temperature
grade part, the KSZ8842-PMQLI will also available from
Q1, 2006. The KSZ8842P is a proven, 4th generation,
integrated, fully managed Layer 2 switch that is entirely
compliant to IEEE802.3u standards.
The KSZ8842P can be configured as a low-latency re-
peater to allow for ‘cut thru’ in latency critical Embedded or
Industrial Ethernet applications. For industrial automation
applications, it runs in half-duplex mode.
The KSZ8842P offers an extensive feature set that includes
tag/port-based VLAN, QoS priority management, MAC
filtering function, MIB counters, and CPU control/data
interfaces to effectively address both current and emerg-
ing Fast Ethernet applications.
The KSZ8842P contains two 10/100 transceivers with
patented mixed-signal low-power technology, two 1K
entry media access control (MAC) units, a separate
DMA channel, a high-speed non-blocking switch fabric,
a dedicated 1K entry forwarding table, and an on-chip
frame buffer memory.
Benefits
In addition to offering all of the features of an integrat-
ed Layer 2 managed switch:
• 2-port switch with 32 bit/33MHz PCI bus for differ-
ent host processor interfaces
• Fully compliant to the IEEE802.3u standard
• Repeater mode capabilities to allow for ‘cut-thru’
in latency critical Industrial Ethernet or Embedded
Ethernet applications
• Dynamic buffer memory scheme
– Essential for applications such as Video over IP
where image jitter is unacceptable
• Micrel LinkMD^TM cable diagnostic capabilities to
determine cable length, determine distance to fault,
and to diagnose faulty cables
• HP Auto MDIX crossover with disable and enable
option
• Industrial temperature support: –40^oC to +85^oC
• Four priority queues to handle voice, video, data,
and control packets
Block Diagram
HP Auto
MDI/MDI-X
HP Auto
MDI/MDI-X
PCI Bus
Interface
10/100
T/TX
PHY 1
10/100
T/TX
PHY 2
32 Bit/33MHz
PCI
Interface Unit
10/100
MAC 1
10/100
MAC 2
DMA
Channel
EEPROM I/F
P1 LED[3:0]
P2 LED[3:0]
Control
Registers
LED
Drivers
1K Look-up
Engine
Queue
Management
Buffer
Management
Frame
Buffers
MIB
Counters
EEPROM
Interface
Note: For an MII/RMII, I²C or SPI interface, use the KSZ8893ML.
LinkMD is a trademark of Micrel, Inc.
Micrel Semiconductor TEL: [phone] FAX: [phone] HTTP:// www.micrel.com