LinkMD is a registered trademark of Micrel, Inc.
Micrel, Inc. TEL: +1 408.944.0800 FAX: + 1 408.474.1000 http://www.micrel.com
Single Port MAC/PHY Controller with Non PCI Interface
The KSZ8851 is a single-port embedded controller chip
with 8/16/32-bit and SPI host interfaces. The device is pin
compatible with Micrel’s KSZ8841 and KSZ8842 product
The KSZ8851 integrates a Fast Ethernet MAC/PHY with
an 8/16/32-bit generic host processor interface and SPI
interface. The device has 18KB of internal buffer memory
shared between the RXQ and TXQ. The buffer memory on
the receive queue is 12KB while the buffer memory for the
transmit queue is 6KB.
The KSZ8851 is designed with flexibility in mind. The
device is designed using a low-power CMOS process
which features programmable IO options of 1.8/2.5/3.3V.
The KSZ8851 supports cable diagnostics feature LinkMD
and Hewlett Packard (HP) Auto-MDIX. The LinkMD
feature determines the length of the cabling plant and also
ascertains if there is an open or short condition in the
cable. Hewlett Packard (HP) Auto-MDIX features
eliminates the need to differentiate between straight or
The KSZ8851 is designed to be fully compliant with the
IEEE 802.3 standards. The KSZ8851 is also available in
industrial grade version.
All datasheets and support documentation can be found
on Micrel’s web site at: www.micrel.com.
KSZ8851 Block Diagram