994 NTBK51 Downloadable D-channel Handler daughterboard
One microprocessor handles data transfer between each serial interface
and software, reports the status of each port and takes commands from the
software to control the activities of the ports. A high performance MPU
supports the D-channel from the PRI card and other software applications
running simultaneously on other ports of the DDCH card.
The microprocessor performs the following functions:
•sanity check and self tests
•message handling between the CS 1000 and the card
•four port serial communication controller handling with Direct Memory
Access (DMA)
•program download from the CS 1000 SSC
Main memory
The main 68EC020 system memory is comprised of 1 Mbyte of SRAM
and is accessible in 8 or 16 bits. The software, base code and application
reside in main RAM and is downloaded from the software through the
shared memory.
The main 68EC020 system memory is comprised of 1 Mbyte of SRAM
and may be accessed in either 8 or 16 bits. The software, base code and
application, resides in main RAM and is downloaded from software through
the shared memory.
The main 68EC020 system memory is comprised of 1 Mbyte of SRAM
and is accessible in 8 or 16 bits. The software, base code and application
reside in main RAM and is downloaded from the software through the
shared memory.
Shared memory
The shared memory is the interface between the CPU and the 68EC020
MPU. This memory is a 16 Kbyte RAM, expandable to 64 kbytesand
accessible in 8 or 16 bits.
The shared memory is the interface between the Option 11C CPU and the
68EC020 MPU. This memory is a 16 Kbyte RAM, expandable to 64 Kbytes
and accessible in either 8 or 16 bits.
The shared memory is the interface between the CS 1000 CPU and the
68EC020 MPU. This memory is a 16 Kbyte RAM, expandableto 64 kbytes
and accessible in 8 or 16 bits.
EPROM memory
The Bootstrap code resides in this 27C1000 EPROM and is executedon
power up or reset.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright© 2003-2008, Nor tel Networks
.