Degree of integration
The level of integration called the absolute number of transistors in an integrated circuit ( English integrated circuit , IC). The degree of integration results from the integration density (number of transistors per unit area) and the chip size (area of the IC).
The degree of integration is also called logical complexity if logic gates are counted instead of transistors . A gate corresponds to about four transistors, as they are required in the prevailing CMOS technology for an unbuffered NAND gate with two inputs. Complex logic circuits such as Field Programmable Gate Arrays (FPGA) are often not implemented internally from individual gates but, for example, with lookup tables . In this case, gate equivalents are counted; H. the number of logic gates that would be necessary to implement this functionality. Complexity information in tag equivalents can only be compared to a limited extent between manufacturers, as there is a large scope for discretion with this information.
Degree of integration or logical complexity are very often characterized with terms such as SSI , MSISp , LSI or VLSI (more rarely also ULSI or SLSI ). SI stands for English scale integration , the respective prefix for the degree of integration, e.g. B. VLSI stands for English very-large-scale integration . These terms are defined inconsistently and very different numbers can be found in the literature. For processors that consist of more than 500 million transistors (e.g. AMD Opteron ), these terms have lost their meaning.
|Abbr.||designation||Complexity (gate equivalents)|
|typical interpretation||Tanenbaum||Texas Instruments|
|SSI||small scale integration||10||1-10||under 12|
|MSI||medium scale integration||100||10-100||12-99|
|LSI||large scale integration||1,000||100-100,000||100-999|
|VLSI||very large scale integration||10,000-100,000||from 100,000||from 1,000|
|ULSI||ultra large scale integration||100,000-1,000,000||-||-|
|SLSI||super large scale integration||1,000,000-10,000,000||-||-|
|ELSI||extra large scale integration||10,000,000-100,000,000||-||-|
|GLSI||giant large scale integration||> 100,000,000||-||-|