NonStop System Glossary

instance
A particular case of a class of items or objects. For example, a process is defined as one instance
of the execution of a program. Multiple processes might be executing the same program
simultaneously. Also, instance data refers to global data of a program or library. Each process
has its own instance of the data.
instance data
For each process using a dynamic-link library, a data segment area containing the global variables
used by the library.
instruction bundle
The three instructions that can be executed in a single CPU cycle.
instruction processing unit (IPU)
A single processing unit that executes programs by fetching instructions from memory and executing
them. See also logical processor.
insulated ground
A grounding conductor with a dielectric (low-conductance) insulator around it to prevent inadvertent
contact with metal conduits.
Intel Itanium instructions
Register-oriented Itanium instructions that are native to and directly executed by a TNS/E system.
Itanium instructions do not execute on TNS and TNS/R systems. Contrast with TNS instructions and
MIPS RISC instructions.
TNS Object Code Accelerator (OCA) produces Itanium instructions to accelerate TNS object code.
A TNS/E native compiler produces native-compiled Itanium instructions when it compiles source
code.
Intel Itanium instruction region
The region of a TNS object file that contains Itanium instructions and the tables necessary to execute
the instructions in accelerated mode on a TNS/E system. The Object Code Accelerator (OCA)
creates this region and writes it into the TNS object file. A TNS object file that contains an Itanium
instruction region can execute in accelerated mode on TNS/E systems. Contrast with MIPS region
of a TNS object file.
Intel Itanium instruction region loading
Mapping the Itanium instructions and any tables necessary at runtime into memory from the Itanium
instruction region of a TNS object file, performed when deemed necessary by the TNS emulation
software on a TNS/E system.
Intel Itanium word
An instruction-set-defined unit of memory. An Itanium word is 4 bytes (32 bits) wide, beginning on
any 4-byte boundary in memory. Contrast with word and TNS word. See also MIPS RISC word.
intelligent SCSI processor (ISP)
The ServerNet addressable controller (SAC) that controls the small computer system interface (SCSI)
bus.
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