IEEE 1076.3-1997

This standard defines standard practices for synthesizing binary digital electronic circuits from VHDL source code. It includes the following: a) The hardware interpretation of values belonging to the BIT and BOOLEAN types deÞned by IEEE Std 1076-1993 and to the STD_ULOGIC type defined by IEEE Std 1164-1993. b) A function (STD_MATCH) that provides "don't care" or "wild card" testing of values based on the STD_ULOGIC type. c) Standard functions for representing sensitivity to the edge of a signal. d) Two packages that deÞne vector types for representing signed and unsigned arithmetic values, and that define arithmetic, shift, and type conversion operations on those types. This standard is designed for use with IEEE Std 1076-1993. Modifications that may be made to the packages for use with the previous edition, IEEE Std 1076-1987, are described in 7.2.

Only some parts of the VHSIC Hardware Description Language (VHDL) are able to be synthesized currently. There are also no current standards describing how to create these needed portable descriptions in VHDL that can be synthesized. This standard will define a set of packages to allow this portability of synthesizable descriptions.

New IEEE Standard - Superseded. The current interpretation of common logic values and the association of numeric values to specific VHDL array types is described. This standard provides semantic for the VHDL synthesis domain, and enables formal verification and simulation acceleration in the VHDL based design. The standard interpretations are provided for values of standard logic types defined by IEEE Std 1164-1993, and of the BIT and BOOLEAN types defined in IEEE Std 1076-1993. The numeric types SIGNED and UNSIGNED and their associated operators define integer and natural number arithmetic for arrays of common logic values. Twos complement and binary encoding techniques are used. The numeric semantic is conveyed by two VHDL packages. This standard also contains any allowable modifications.