dm9332 Davicom Semiconductor, Inc., dm9332 Datasheet - Page 45

• Manufacturer Part Number: dm9332
• Description: 10/100mbps Ethernet Fiber/twisted Pair Single Chip Media Converter
• Manufacturer: Davicom Semiconductor, Inc.

port, see bit 6 of register 61h. The port enters
partition mode when more than 64 consecutive
collisions are occurred. In partition mode the port
continuous to transmit but it will not receive. The port
returned to normal operation mode when a good
packet is seen on the wire. The detail description of
partition mode represent following:
the following conditions occurs:
consecutive re-transmit attempts to the same packet.
for more than 512 bit times.
the transmitting packet is deferred to long.
packet, regardless of the collision detection, and will
not allow the usual Back-off Algorithm. Additional
packets pending for transmission will be transmitted,
while ignoring the internal collision indication. This
frees up the ports transmit buffers which would
otherwise be filled up at the expense of other ports
buffers.
signifying
connection/cable/station), thus dropping packets is a
small price to pay vs. the cost of halting the switch
due to a buffer full condition.
end of a successful packet transmission.
successful packet transmission is defined as no
collisions were detected on the first 512 bits of the
transmission.
broadcast or multicast packets, to protect the switch
from lower bandwidth availability.
one is throttling broadcast packet only, the other
includes multicast. This feature can be set through bit
1 of register 61h.
Preliminary datasheet
DM9332-15-DS-P01
August 26, 2009
The DM9332 provides a partition mode for each
(1). Entering Partition State
A port will enter the Partition State when either of
(2). While in Partition state:
The port will continue to transmit its pending
(3). Exiting from Partition State
The Port exits from Partition State, following the
The DM9332 has an option to limit the traffic of
There are two types of broadcast storm control,
The
9.2.9 Partition Mode
The port detects a collision on every one of 64
The port detects a single collision which occurs
Transmit defer timer time out, which indicates
9.2.10 Broadcast Storm Filtering
broadcast
The assumption is that the partition is
a
system
storm
failure
threshold
10/100Mbps Ethernet Fiber/Twisted Pair Single Chip Media Converter
situation
can
(bad
be
A
programmed by EEPROM or register 67h, the default
setting is no broadcast storm protecting.
control for each port. One is the ingress and egress
bandwidth rate can be controlled separately, the
other is combined together, this function can be set
through bit 3 of register 61h. The bandwidth control is
disabled by default.
threshold rate is defined in register 66h. For
combined mode, it is defined in register 67h.
is enabled, Pause or Jam packet will be transmitted.
The ingress packets will be dropped if flow control is
disabled.
transmit any packets. On the other hand, the ingress
bandwidth of source port will be throttled that prevent
packets from forwarding.
egress bandwidth over threshold, the bandwidth will
be throttled.
on per port base, detail as below:
port” by register 52h, multiple ports can be set as
“receive monitor port” or “transmit monitor port” in
per-port register 65h.
are send a copy to “sniffer port”. For example, port 0
is set as “receive monitor port” and port 2 is selected
as a “sniffer port”. If a packet is received form port 0
and predestined to port 1 after forwarding decision,
the DM9332 will forward it to port 1 and port 2 in the
end.
port” are send a copy to “sniffer port”. For example,
port 1 is set as “transmit monitor port” and port 2 is
selected as “sniffer port”. If a packet is received from
port 0 and predestined to port 1 after forwarding
decision, the DM9332 will forward it to port 1 and port
The DM9332 supports two types of bandwidth
To
The behavior of bandwidth control as below:
(1).For the ingress control, if flow control function
(2).For the egress control, the egress port will not
(3).In combined mode, if the sum of ingress and
The DM9332 supports “Port Monitoring” function
(1). Sniffer Port and Monitor Port
There is only one port can be selected as “sniffer
(2).Receive monitor
All packets received on the “receive monitor port”
(3).Transmit monitor
All packets transmitted on the “transmit monitor
9.2.11 Bandwidth Control
9.2.12 Port Monitoring Support
separate
bandwidth
control
DM9332
mode,
the
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