KSZ8842-16/32
MQL/MVL/MVLI
2-Port Ethernet Switch with Non-PCI Interface
Data Sheet Rev 1.4
General Description
The KSZ8842-series of 2-port switches includes PCI and
non-PCI CPU interfaces, and are available in 8/16-bit
and 32-bit bus designs (see Ordering Information).
This datasheet describes the KSZ8842M-series of non-
PCI CPU interface chips. For information on the
KSZ8842 PCI CPU interface switches, refer to the
KSZ8842P datasheet.
The KSZ8842M offers an extensive feature set that
includes tag/port-based VLAN, quality of service (QoS)
priority management, management information base
(MIB) counters, and CPU control/data interfaces to
effectively address Fast Ethernet applications.
The KSZ8842M contains: Two 10/100 transceivers with
patented, mixed-signal, low-power technology, two
media access control (MAC) units, a direct memory
access (DMA) channel, a high-speed, non-blocking,
switch fabric, a dedicated 1K entry forwarding table, and
an on-chip frame buffer memory.
The KSZ8842M is the industry’s first fully managed, 2-
port switch with a non-PCI CPU interface. It is based on
a proven, 4th generation, integrated Layer-2 switch,
compliant with IEEE 802.3u standards. Also an industrial
temperature grade version of the KSZ8842, the
KSZ8842MQLI, can be ordered (see Ordering
Information).
The KSZ8842M can be configured as a switch or as a
low-latency (≤ 310 nanoseconds) repeater in latency-
critical, embedded or industrial Ethernet applications.
For industrial applications, the KSZ8842M can run in
half-duplex mode regardless of the application.
Functional Diagram
1 K lo o k -u p
E n g in e
P 1 H P A u to
M D I/M D I-X
1 0 /1 0 0 B a s e -
T /T X
1 0 /1 0 0
M A C
1
P H Y
1
S c h e d u lin g
M a n a g e m e n t
P 2 H P A u to
M D I/M D I-X
1 0 /1 0 0 B a s e -
T /T X
1 0 /1 0 0
M A C
2
P H Y
2
B u ffe r
M a n a g e m e n t
R X Q
4 K B
Q M U
D M A
C h a n n e l
S w itc h
H o s t
N o n -P C I
C P U
M A C
T X Q
4 K B
d e d
E m b e d
P ro c e s
B u s
In te rfa c e
U n it
rfa c e
F ra m e
B u ffe rs
s o r In te
C o n tro l
R e g is te rs
8 ,1 6 , o r 3 2 -b it
G e n e ric H o s t
In te rfa c e
M IB
C o u n te rs
P 1 L E D [3 :0 ]
P 2 L E D [3 :0 ]
L E D
D riv e rs
E E P R O M
In te rfa c e
E E P R O M I/F
Figure 1. KSZ8842M Functional Diagram
November 2005
1
Rev. 1.4