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TLF12437
DP83957
10
Mbs
Repeater
Information
Base
PRELIMINARY
June 1995
DP83957 10 Mbs Repeater Information Base
General Description
The DP83957 Repeater Information Base ‘‘RIB’’ allows ef-
fective implementation of managed multi-port 10 Mbs
ethernet repeater hubs The device supports all the neces-
sary Port Attributes for the IEEE 8023k standard (Layer
Management for 10 Mbs Baseband Repeaters) This de-
vice is designed to be interfaced with Repeater Interface
Controllers (DP839502) and gathers attributes on a per-
port per-packet basis
The DP83957 collects management attributes via the
DP839502 Management Bus and stores this information in
an external SRAM The DP83957 can be programmed to
collect information for up to two DP839502 on a shared
Management Bus It can also be used in a dedicated one
DP83957 per DP839502 architecture The attributes stored
in external SRAM can be easily accessed through the
DP83957 by an 8-bit multiplexed AddressData bus
Features
Y
Fully IEEE 8023K-July 1992 compatible
Y
Supports up to two DP839502
Y
Supports generic 1kx8or2kx8 SRAMs with variable
access times of up to 45 ns
Y
Guarantees at least one attribute access by the micro-
processor in the busiest network scenario
Y
Pipelined architecture for processing back to back
frames
Y
Supports maskable interrupts for status and error re-
porting on a shared interrupt pin
Y
Detection and notification of DP83950 Management
Bus errors
Y
Detection and notification of overflow of attribute coun-
ters
Y
80-pin PQFP package
10 System Diagram
TLF12437 – 1
TRI-STATE
is a registered trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation
RRD-B30M105Printed in U S A