Circuit Pack Descriptions
7-12 Issue 8.0 July 2002
General Description of Operation 7
The SYSMEM circuit pack provides the following:
■ Nonvolatile program (executable code) and configuration (data) memory
■ Office alarms interface
■ User panel LEDs and controls
■ Parallel telemetry interface (FT-2000 OC-48 Add/Drop-Rings Terminals
only)
■ User-settable miscellaneous discrete interface.
Detailed Description of Operation 7
Memory 7
Nonvolatile Program (Executable Code) Storage. 7Figure 7-4 shows a functional
block diagram of the SYSMEM circuit pack. The nonvolatile program storage is
provided by 4 megabytes of flash erasable programmable read-only memory
(flash-EPROM). This contains the main system software for all the controllers in
the system (for example, System Controller, Line Controllers, and board
controllers). Flash-EPROM combines the nonvolatility of EPROM with the
in-circuit reprogramming ability of electrically erasable programmable read-only
memory (EEPROM). Flash-EPROM allows in-service software upgrades to be
performed locally or remotely (via modem connections).
Nonvolatile Configuration (Data) Storage. 7The nonvolatile configuration storage is
provided by 128 kilobytes of EEPROM. This contains all system state and
user-provisioned data. This includes all system parameters with their original and
current values. EEPROM is byte erasable and writable. This allows configuration
information to be easily changed during system operation.
Nonvolatile Memory. 7The nonvolatile memory consists of 128 bytes of EEPROM.
The nonvolatile memory is used to store information about the history of the
SYSMEM circuit pack such as the
CLEI
code and type/version information.
For more information about memory administration, refer to Volume I, Section 8,
“Administration and Provisioning.”
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