Circuit Pack Descriptions
Issue 8.0 July 2002
7-7
The sanity check circuitry detects hardware and software faults. When a fault
occurs, the microprocessor is reset and the FAULT LED on the circuit pack
faceplate is lighted.
General Description of Operation 7
The SYSCTL circuit pack provides overall administrative control of the FT-2000
OC-48 Lightwave System. It performs system-wide computations and
performance monitoring. It also provides the serial user interfaces.
The SYSCTL circuit pack also interfaces with the System Memory (SYSMEM),
Line Controller (LNCTL), Overhead Controller - Terminal [OHCTL (TERM)], and
Overhead Controller - Tributary (TOHCTL) (Release 6 and later) circuit packs.
Detailed Description of Operation 7
Control Circuitry 7
Microprocessor . 7Figure 7-2 provides an overall block diagram of the SYSCTL
circuit pack. The SYSCTL circuit pack is the highest level processor in the
three-level control hierarchy of the FT-2000 OC-48 Lightwave System.
Memory 7
Start-Up Memory . 7The start-up memory consists of 64 kilobytes of read-only
memory. The start-up memory contains the program that allows the
microprocessor to copy the executable code and data for the system from the
nonvolatile memory of the SYSMEM circuit pack into the operating memory of the
SYSCTL circuit pack. This allows the microprocessor to start up operation during
a power-up or a reset condition or when initializing new software. The SYSCTL
circuit pack also has a unique network services access point (NSAP) code in the
read-only memory. This is required for bidirectional ring applications.
Operating Memory . 7The main operating memory consists of 4 megabytes of
dynamic random access memory (DRAM). Direct memory access (DMA) allows
the SYSCTL circuit pack to copy the executable code and data for the system
from the nonvolatile memory of the SYSMEM circuit pack into the operating
memory during a power-up or reset condition, or when initializing new software.
Nonvolatile Memory . 7The nonvolatile memory consists of 128 bytes of
electrically-erasable programmable read-only memory (EEPROM). The
nonvolatile memory is used to store information about the history of the SYSCTL
circuit pack such as the
Common Language
*
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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