|
|
PDF NWK954D Data sheet ( Hoja de datos )
| Número de pieza | NWK954D | |
| Descripción | QUAD FAST ETHERNET REPEATER | |
| Fabricantes | Mitel Networks | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de NWK954D (archivo pdf) en la parte inferior de esta página. Total 17 Páginas | ||
|
No Preview Available !
Supersedes January 1998 version, DS4842 - 1.1
The NWK954 is a fully integrated, unmanaged, 4-port Fast
Ethernet Repeater conforming to the IEEE 802.3 100BASE-TX
Standard. The device integrates the 802.3 Repeater functions
with four 100BASE-TX PHY modules, enabling direct connection
to the isolation transformers with no additional PHY components.
It has built-in LED drivers for display of port activity and
network utilization. There is a local expansion port which allows
up to six NWK954s to be cascaded to form a 24-port repeater
with no additional components.
With the addition of simple backplane driver/receivers, up to
eight 24-port repeaters can be stacked.
The NWK954 is supplied in a 128-pin PQFP and interfaces
to the twisted pair media through 1:1 isolation transformers.
ORDERING INFORMATION
NWK954D/CG/GH1N
NWK954
QUAD FAST ETHERNET REPEATER
PRELIMINARY INFORMATION
DS4842-2.1 April 1998
FEATURES
s Compliant with IEEE 802.3 100BASE-TX Repeater
Unit Specification
s Incorporates four IEEE 802.3 Compliant 100BASE-TX
Ports
s Local Expansion Port for Cascading to 24 Ports
s Stackable Backplane for Expansion up to 192 Ports
s Link/Activity LED and Receive Error LED for each Port
s Collision LED
s Five LED Network Utilization Display
s Base Line Wander Correction
s Power Saving on Unused Ports
s Driven from a Single 25MHz Clock
s Single 5V supply
s Low Power CMOS Technology
s 128-pin PQFP package
BACKPLANE CONTROLS
BACKPLANE BUFFERS
OSCILLATOR
CLOCK DRIVERS
LOCAL EXPANSION BUS
NWK954
NWK954
NWK954
QUAD
MAGNETICS
QUAD RJ45
QUAD
MAGNETICS
QUAD
MAGNETICS
NWK954
QUAD
MAGNETICS
Fig. 1 System block diagram
NWK954
QUAD
MAGNETICS
NWK954
QUAD
MAGNETICS
1 page  
Basic Repeater Function
The Repeater Controller monitors activity on the 4 twisted
pair ports and on the Expansion Port. When a packet is received
on one of the twisted pair ports it is forwarded to the other 3
twisted pair ports and to the Expansion Port. When a packet is
received on the Expansion Port it is forwarded to all 4 twisted
pair ports. When receive activity is detected on 2 or more ports
the Repeater Controller will send the jam signal to all twisted
pair ports for the duration of all activity associated with the
collision event.
Jabber Protection
The Repeater Controller provides receive jabber protection
to ensure that the network is not disrupted by excessively long
data streams. If a received data stream exceeds 65,536 bit times
then the receiving port will be shutdown. In the shutdown state
data received on the faulty port is ignored and packets received
from other ports are not transmitted to the faulty port. A port will
recover from the shutdown state when the incoming data stream
ends or if the device is reset.
Auto-Partition Function
The auto-partition function prevents faulty behaviour on a
network segment from disrupting the entire network. The
Repeater Controller counts consecutive collisions on each port
and will partition a port that causes more than 60 consecutive
collisions. In the partitioned state, packets received on the faulty
port will be ignored but packets received from other ports will
continue to be transmitted to the faulty port. The port will recover
from the partitioned state when valid activity is detected on the
port or if the device is reset.
Carrier Integrity Monitor
The Repeater Controller detects false carrier events on all
ports. A false carrier is defined as receive activity that does not
commence with the correct start-of-packet sequence. When a
false carrier event is detected, the Repeater Controller will
transmit the jam signal on all ports for the duration of the false
carrier event provided it does not exceed 450-500 bit times.
After this time the port will be isolated and the jam signal will
cease. The NWK954 will also isolate a port that suffers 2
successive false carrier events. In the isolated state, packets
received from the faulty port are ignored and packets received
from other ports are not transmitted to the faulty port. A port will
recover from the isolated state when a valid inter-packet gap is
detected and is followed by either a valid packet exceeding 450-
500 bit times or by an idle sequence exceeding 33000 (±25%)
bit times.
Expansion Port
The Expansion Port allows up to 6 NWK954s to be cascaded.
This allows a 24-port hub to be built with no additional external
components. The Expansion Port includes a 5-bit parallel
bidirectional data bus (IRD) which carries unscrambled symbol data
and a 25MHz sampling clock (BPCLK). Each NWK954 indicates
receive activity on any of its 4 twisted pair ports by asserting the
local activity output (LACTOUT_N). The LACTOUT_N signals from
each NWK954 connect to the local activity inputs (LACTIN_N) of all
the other cascaded NWK954s.
When a collision occurs between 2 twisted pair ports on an
NWK954, the event is communicated to other cascaded NWK954s
by asserting the collision signal (BPCOL_N). This instructs all
cascaded NWK954s to transmit the jam signal for the duration of
the collision event. BPCOL_N is also asserted when a collision occurs
between 2 twisted pair ports on different NWK954s.
Backplane
The Expansion Port allows hubs to be stacked via a backplane
bus. This requires the addition of some simple external driver/
receivers. The functional requirement for these components is
illustrated in Fig. 6. Contact Mitel for full details of recommended
components.
NWK954
BPACTIN_ N [7:1]
5
LACTIN_N [5:1]
LACTOUT_N
BPCOLIN_N TXCLKIN
BPCOL_N
BPCLK
5
IRD [4:0]
BPACTIN_ N [7:1]
5
LACTIN_N [5:1]
LACTOUT_N
BPCOLIN_N TXCLKIN
BPCOL_N
BPCLK
5
IRD [4:0]
BPACTIN_ N [7:1]
5
LACTIN_N [5:1]
LACTOUT_N
BPCOLIN_N TXCLKIN
BPCOL_N
BPCLK
5
IRD [4:0]
BPACTIN_ N [7:1]
5
LACTIN_N [5:1]
LACTOUT_N
BPCOLIN_N TXCLKIN
BPCOL_N
BPCLK
5
IRD [4:0]
BPACTIN_ N [7:1]
5
LACTIN_N [5:1]
LACTOUT_N
BPCOLIN_N TXCLKIN
BPCOL_N
BPCLK
5
IRD [4:0]
BPACTIN_ N [7:1]
5
LACTIN_N [5:1]
LACTOUT_N
BPCOLIN_N TXCLKIN
BPCOL_N
BPCLK
5
IRD [4:0]
CLOCK
DRIVER
25MHz
OSCILLATOR
Fig. 5 Cascaded NWK954s
5
5 Page 
LED Drivers
Signal
COLLED_N
P0_RXLED_N
P1_RXLED_N
P2_RXLED_N
P3_RXLED_N
P0_ERLED_N
P1_ERLED_N
P2_ERLED_N
P3_ERLED_N
ACTLED_N4
ACTLED_N3
ACTLED_N2
ACTLED_N1
ACTLED_N0
Pin no.
109
124
122
120
118
123
121
119
117
116
115
114
113
112
Clocks and Controls
Signal
TXCLKIN
Pin no.
86
RESET_N
5
PSEN0
PSEN1
TA4
TA3
TA2
87
88
13
14
15
NWK954
Type
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital output
Standard
digital outputs
Description
Collision LED. Drives an LED to indicate that a collision
has occurred either locally or elsewhere in the stack.
Port 0 activity LED. Drives an LED to indicate link/activity
on port 0. The LED is turned on when a link is established
and flashes off when a packet is being received.
Port 1 activity LED. Drives an LED to indicate link/activity on
port 1. The LED is turned on when a link is established and
flashes off when a packet is being received.
Port 2 actlvlty LED. Drives an LED to indicate link/activity on
port 2. The LED is turned on when a link is established and
flashes off when a packet is being received.
Port 3 activlty LED. Drives an LED to indicate link/activity on
port 3. The LED is turned on when a link is established and
flashes off when a packet is being received.
Port 0 error LED. Drives an LED to indicate an error on
port 0. See the text for a full description.
Port 1 error LED. Drives an LED to indicate an error on
port 1. See the text for a full description.
Port 2 error LED. Drives an LED to indicate an error on
port 2. See the text for a full description.
Port 3 error LED. Drives an LED to indicate an error on
port 3. See the text for a full description.
Utilization LEDs. Drives 5 LEDs to indicate utilization of the
network segment. See the text for a full description.
Table 6
Type
Description
Digital input
no pull-up
Open drain
digital output and
digital input,
no pull-up
Digital inputs
with pull-ups
Digital inputs,
no pull-ups
25MHz reference clock. Supplied from an external source
to all NWK954s on the local expansion bus.
Asynchronous reset. This signal is driven low by the on-
chip power-on reset circuit, but may also be driven low
externally for manual reset. Must be pulled high by an
external 5kΩ resistor.
Power-savlng enables. 11 enables power-saving on all
ports. 01 suppresses power saving on port 0, 10
suppresses power saving on port 3, 00 suppresses power-
saving on all ports.
Scrambler seed. Each ot the four PHY modules in the
NWK954 is provided with a unique scrambler seed derived
from TA[4:2]. To ensure that all ot the local PHYs have
unique scrambler seeds, each NWK954 connected to the
local expansion bus should have its TA[4:2] input set to a
unique value by connecting to DIGVDD or DIGGND.
Table 7
11
11 Page | ||
| Páginas | Total 17 Páginas | |
| PDF Descargar | [ Datasheet NWK954D.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| NWK954 | QUAD FAST ETHERNET REPEATER | Mitel Networks |
| NWK954CG | QUAD FAST ETHERNET REPEATER | Mitel Networks |
| NWK954D | QUAD FAST ETHERNET REPEATER | Mitel Networks |
| NWK954GH1N | QUAD FAST ETHERNET REPEATER | Mitel Networks |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |