DP83950BVQB National Semiconductor, DP83950BVQB Datasheet - Page 27

• Manufacturer Part Number: DP83950BVQB
• Description: IC CTRLR RIC REPEATER 160-PQFP
• Manufacturer: National Semiconductor

Specifications of DP83950BVQB

• Controller Type: Ethernet Repeater Interface Controller
• Interface: IEEE 802.3
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 380mA
• 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: *DP83950BVQB

5 0 Functional Description
Note 1 Refer to note on page 25 for the transmit collision case
RIC Receiving
RIC Receiving
RIC Receiving
RIC Receiving
required for a
required for a
required for a
required for a
RIC to drive
RIC to drive
RIC to drive
RIC to drive
Conditions
Conditions
Conditions
Conditions
this signal
this signal
this signal
this signal
the Signal
the Signal
the Signal
the Signal
Function
Function
Function
Function
PORT M
PORT M (Note 1)
This signal denotes there is activity
on PORT N or PORT M
A RIC must contain PORT N or
Note Although this signal normally has
only one source asserting the signal active
it is used in a wired-or configuration
The signal is monitored by all RICs in
the repeater system
This signal denotes that a repeater
port that is not PORT N or PORT M
is experiencing a collision
Any RIC which satisfies the above
condition
Note This bus line is used in a wired-or
configuration
The signal is monitored by all RICs in
the repeater system
Denotes PORT N or PORT M is
experiencing a collision
A RIC must contain PORT N or
The Signal is monitored by all other
RICs in the repeater system
This signal acts as an activity
framing signal for the IRC and IRD
signals
A RIC must contain PORT N
The Signal is monitored by all other
RICs in the repeater system
ANYXN
ACTN
COLN
IRE
(Continued)
27
COLLISION state In order for the arbitration chain to func-
Methods of RIC Cascading
In order to build multi-RIC repeaters PORT N and PORT M
identification must be performed across all the RICs in the
system Inside each RIC the PSMs are arranged in a logical
arbitration chain where port 1 is the highest and port 13 the
lowest The top of the chain the input to port 1 is accessible
to the user via the RIC’s ACKI input pin The output from the
bottom of the chain becomes the ACKO output pin In a
single RIC system PORT N is defined as the highest port in
the arbitration chain with receive or collision activity Port N
identification is performed when the repeater is in the IDLE
state PORT M is defined as the highest port in the chain
with a collision when the repeater leaves the TRANSMIT
tion all that needs to be done is to tie the ACKI signal to a
logic high state In multi-RIC systems there are two methods
to propagate the arbitration chain between RICs
The first and most straight forward is to extend the arbitra-
tion chain by daisy chaining the ACKI ACKO signals be-
tween RICs In this approach one RIC is placed at the top of
the chain (its ACKI input is tied high) then the ACKO signal
from this RIC is sent to the ACKI input of the next RIC and
so on This arrangement is simple to implement but it places
some topological restrictions upon the repeater system In
particular if the repeater is constructed using a backplane
with removable printed circuit boards (These boards con-
tain the RICs and their associated components) If one of
the boards is removed then the ACKI ACKO chain will be
broken and the repeater will not operate correctly
RIC Receiving
RIC Receiving
required for a
required for a
RIC to drive
RIC to drive
Conditions
Conditions
this signal
the Signal
this signal
the Signal
Function
Function
Decoded serial data in NRZ format
received from the network segment
attached to PORT N
A RIC must contain PORT N
The signal is monitored by all other
RICs in the repeater system
Clock signal associated with IRD
and IRE
A RIC must contain PORT N
The signal is monitored by all other
RICs in the repeater system
IRD
IRC