KS8999
Integrated 9-Port 10/100 Switch with
PHY and Frame Buffer
Rev 1.14
General Description
The KS8999 contains eight 10/100 physical layer
transceivers, nine MAC (Media Access Control) units
with an integrated layer 2 switch. The device runs in two
modes. The first mode is an eight port integrated switch
and the second is as a nine port switch with the ninth
port available through an MII (Media Independent
Interface). Useful configurations include a stand alone
eight port switch as well as a eight port switch with a
routing element connected to the extra MII port. The
additional port is also useful for a public network
interfacing. The KS8999 is designed to reside in an
unmanaged design not requiring processor intervention.
This is achieved through I/O strapping or EEPROM
programming at system reset time. On the media side,
the KS8999 supports 10BaseT, 100BaseTX and
100BaseFX as specified by the IEEE 802.3 committee.
Physical signal transmission and reception are
enhanced through use of analog circuitry that makes the
design more efficient and allows for lower power
consumption and smaller chip die size.
Data sheets and support documentation can be found
on Micrel’s web site at www.micrel.com.
Functional Diagram
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
January 2005
KS8999
MICREL [ MICREL SEMICONDUCTOR ]
