DP83953VUL National Semiconductor, DP83953VUL Datasheet - Page 24

• Manufacturer Part Number: DP83953VUL
• Description: IC CTRLR RIC REPEATER 160-PQFP
• Manufacturer: National Semiconductor

Specifications of DP83953VUL

• Controller Type: Ethernet Repeater Interface Controller
• Interface: IEEE 802.3
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 870mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 160-MQFP, 160-PQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *DP83953VUL

4.0 Functional Description
on its segment, but in addition it is higher in the arbitration
chain. This priority yields no benefits for port A1 since the
ANYXN signal is still active. There are now two sources
driving ANYXN, the MSMs and the collision on port B1.
Eventually the collision on port B1 ends and the ANYXN
extension by the MSMs expires. There is only one collision
on the network (this may be deduced since ANYXN is inac-
tive) so the repeater will move to the ONE PORT LEFT
state. The RIC2A system treats this state in a similar man-
ner to a receive collision with PORT M fulfilling the role of
the receiving port. The difference from a true receive colli-
sion is that the switch from packet data to the jam pattern
has already been made (controlled by ANYXN). Thus the
state of COLN has no effect upon repeater operations. In
common with the operation of the RECEIVE COLLISION
state, the repeater remains in this condition until the colli-
sion and receive activity on PORT M subside. The packet
repetition operation completes when the Tw1 recovery time
in the WAIT state has been performed.
Note: In transmit collision conditions
which contained PORT N at the start of packet repetition contains PORT M
during the TRANSMIT COLLISION and ONE PORT LEFT states.
COLN
will only go active if the RIC2A
(Continued)
24
Jabber Protection
A repeater is required to disable transmit activity if the
length of its current transmission reaches the jabber pro-
tect limit. This is defined by the specification's Tw3 time.
The repeater disables output for a time period defined by
the Tw4 specification, after this period normal operation
may resume.
Figure 9 shows the effect of a jabber length packet upon a
RIC2A based repeater system. The JABBER PROTECT
state is entered from the SEND DATA state. While the Tw4
period is observed the Inter-RIC bus displays the IDLE
state. This is misleading since new packet activity or contin-
uous activity (as shown in the diagram) does not result in
packet repetition. This may only occur when the Tw4 re-
quirement has been satisfied.
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