Nortel Communication Server 100 Manual page 29

Memory
The Local Carrier Interface memory stores the following programs and
data:
•
Boot code, self-test code, and operating firmware are stored in the
EPROM.
•
Data is stored in the RAM.
•
Code that is downloaded by the local system CPU to the Local Carrier
Interface card MPU and main function code is stored in the RAM.
•
Data containing the Local Carrier Interface card identification and
version is stored in the EEPROM.
CPU to MPU bus interface
Information exchange between the system CPU and the Local Carrier
Interface MPU is performed with packetized messages transmitted over
the CPU bus.
This interface uses shared Static Random Access Memory (SRAM) as a
communication exchange point between the CPU and the MPU. Both the
CPU and the MPU can access this memory over the transmit and receive
channels on the CPU bus.
Network bus interface
The network bus interface performs two major functions:
•
converts bit interleaved serial data received from the network bus into
byte interleaved data for transmission over the timeslots used by the
IVD bus
•
accepts byte-interleaved data transmitted from the IVD bus and
converts it into a bit-interleaved data stream for transmission over the
network bus
Carrier interface
Each Local Carrier Interface card has three T1/E1 interfaces to provide
two primary links and a spare, or three primary T1 or E1 carrier links.
Each T1 or E1 carrier interface is switch-selectable to a 1.5 Mbps T1 or
a 2 Mbps E1 point-to-point transmission facility. A carrier interface card
does not support a combination of T1 and E1 carrier links on a carrier link;
it supports only T1 or E1 carriers.
Nortel Communication Server 1000
Carrier Remote IPE Fundamentals
NN43021-555 04.01 4 June 2010
Copyright © 2007-2010 Nortel Networks. All Rights Reserved.
Functional description 29