Main Memory; Shared Memory; Eprom Memory; Flash Eprom Memory - Nortel Enterprise 1000 Reference Manual

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Main Memory

Shared Memory

EPROM Memory

Flash EPROM Memory

EEPROM Memory

Serial Communication Controller

553-3023-211 Standard 1.00 June 2001
NTBK51 Downloadable D-channel Handler daughterboard
The microprocessor performs the following functions:
• Sanity check and self tests
• Message handling between the Succession CSE 1000 and the card
• Four port serial communication controller handling with Direct Memory
Access (DMA)
• Program download from the Succession CSE 1000 CPU
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 shared memory is the interface between the Succession CSE 1000 CPU
and the 68EC020 MPU. This memory is a 16 Kbyte RAM, expandable to
64 kbytes and accessible in 8 or 16 bits.
The Bootstrap code resides in this 27C1000 EPROM and is executed on
power up or reset.
Flash EPROM provides non-volatile storage for the DDCH loadware which
minimizes the impact to sysload. The Flash EPROM provides an increase in
system service with a reduced delay after a brown-out, and faster testing of a
hardware pack after it is plugged in.
The DDCH uses a 1024 bit serial EEPROM for storing the Nortel Networks
product code and a revision level. This information can be queried by the
software.
The serial controller is the Zilog Z16C35 and is referenced as the Integrated
Controller (ISCC). The ISCC includes a flexible Bus Interface Unit (BIU)
and four Direct Memory Access (DMA) channels, one for each receive and