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Encyclopedia > Library (electronics)

In electronic design, library often refers to a collection of cells, macros or functional units that perform common operations and are used to build more complex logic blocks. Image File history File links Merge-arrow. ... Standard Cell design involves compiling Hardware definition Language HDL designs into standard logic libraries. ... Image File history File links Wikitext. ... This article is about the engineering discipline. ...


A standard cell library is a collection of low level logic functions such as AND, OR, INVERT, flip-flops, latches and buffers. These cells are realized as fixed height, variable width full custom cells. The key aspect with these libraries is that they are of a fixed height, which enables them to be placed in rows, easing the process of automated digital layout. The cells are typically optimised full custom layouts, which minimise delays and area.


A typical standard cell library contains two main components:

  1. Timing Abstract (This is generally in the Synopsys Liberty format)
    This provides functional definitions, timing, power and noise information for each cell.
  2. Layout Abstract (Common formats that are in use are the Cadence LEF format, and the Synopsys Milkyway format)
    These contain reduced information about the cell layouts, which is sufficient for automated "Place and Route" tools.

They also may contain the following additional components:

  1. A full layout of the cells
  2. Spice models of the cells
  3. Verilog models or VHDL Vital models
  4. Parasitic extraction models
  5. DRC rule decks

An example is a simple XOR logic gate, which can be formed from OR, INVERT and AND gates.


  Results from FactBites:
 
EMIS ELibM: Mathematical Journals (5374 words)
The Electronic Journal of Linear Algebra, a publication of the International Linear Algebra Society (ILAS), is a refereed all-electronic journal that welcomes mathematical articles of high standards that contribute new information and new insights to matrix analysis and the various aspects of linear algebra and its applications.
Electronic Transactions on Numerical Analysis (ETNA) is an electronic journal for the publication of significant new and important developments in numerical analysis and scientific computing.
The free access to the electronic versions of both journals is based on the distribution of their print versions, which are available from the Library of I.
eLib: Electronic Libraries Programme (1722 words)
Library Resource Sharing and Discovery: Catalogues for the 21st Century: details now available of a one day workshop (in two locations) on the 3rd of March 2000 (London) and the 11th April 2000 (Glasgow) presented by the eLib CLUMP projects and co-ordinated by UKOLN.
The conference is being organised by the Electronic Libraries Programme and co-ordinated by UKOLN.
An electronic version of the eLib Supporting study "An Investigation into the Digital Preservation needs of Universities and Research Funders" by Denise Lievesley and Simon Jones of the Data Archive at the University of Essex, is now available.
  More results at FactBites »

 

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