|Summary |Design Units |Sequential Statements |Concurrent Statements |Predefined Types |Declarations |
|Resolution and Signatures |Reserved Words |Operators |Predefined Attributes |Standard Packages |
abs operator, absolute value of right operand. No () needed. access used to define an access type, pointer after specifies a time after NOW alias create another name for an existing identifier all dereferences what precedes the .all and operator, logical "and" of left and right operands architecture a secondary design unit array used to define an array, vector or matrix assert used to have a program check on itself attribute used to declare attribute functions begin start of a begin end pair block start of a block structure body designates a procedure body rather than declaration buffer a mode of a signal, holds a value bus a mode of a signal, can have multiple drivers case part of a case statement component starts the definition of a component configuration a primary design unit constant declares an identifier to be read only disconnect signal driver condition downto middle of a range 31 downto 0 else part of "if" statement, if cond then ... else ... end if; elsif part of "if" statement, if cond then ... elsif cond ... end part of many statements, may be followed by word and id entity a primary design unit exit sequential statement, used in loops file used to declare a file type for start of a for type loop statement function starts declaration and body of a function generate make copies, possibly using a parameter generic introduces generic part of a declaration group collection of types that can get an attribute guarded causes a wait until a signal changes from False to True if used in "if" statements impure an impure function is assumed to have side effects in indicates a parameter in only input, not changed inertial signal characteristic, holds a value inout indicates a parameter is used and computed in and out is used as a connective in various statements label used in attribute statement as entity specification library context clause, designates a simple library name linkage a mode for a port, used like buffer and inout literal used in attribute statement as entity specification loop sequential statement, loop ... end loop; map used to map actual parameters, as in port map mod operator, left operand modulo right operand nand operator, "nand" of left and right operands new allocates memory and returns access pointer next sequential statement, used in loops nor operator, "nor" of left and right operands not operator, complement of right operand null sequential statement and a value of used in type declarations, of Real ; on used as a connective in various statements open initial file characteristic or operator, logical "or" of left and right operands others fill in missing, possibly all, data out indicates a parameter is computed and output package a design unit, also package body port interface definition, also port map postponed make process wait for all non postponed process to suspend procedure typical programming procedure process sequential or concurrent code to be executed pure a pure function may not have side effects range used in type definitions, range 1 to 10; record used to define a new record type register signal parameter modifier reject clause in delay mechanism, followed be a time rem operator, remainder of left operand divided by right op report statement and clause in assert statement, string output return statement in procedure or function rol operator, left operand rotated left by right operand ror operator, left operand rotated right by right operand select used in selected signal assignment statement severity used in assertion and reporting, followed by a severity signal declaration that an object is a signal shared used to declare shared objects sla operator, left operand shifted left arithmetic by right op sll operator, left operand shifted left logical by right op sra operator, left operand shifted right arithmetic by right srl operator, left operand shifted right logical by right op subtype declaration to restrict an existing type then part of if condition then ... to middle of a range 1 to 10 transport signal characteristic type declaration to create a new type unaffected used in signal waveform units used to define new types of units until used in wait statement use make a package available to this design unit variable declaration that an object is a variable wait sequential statement, also used in case statement when used for choices in case and other statements while kind of loop statement with used in selected signal assignment statement xnor operator, exclusive "nor" of left and right operands xor operator, exclusive "or" of left and right operands