合肥工业大学：EDA技术与应用（精品课程）：p281_ex9_22_concurrent_statement_PROCEDURE_adder

-- VHDL code position: p280_ex9_22_concurrent_statement_procedure_adder -- Note : This is code for explaing concurrent procedure call -- in concurrent_statement of VHDL -- -- See Also: example 9_22, 9_23, 9_24 -- Debug : no debug --------------------------------------------------------------------------------- -- 7 kinds of concurrent statement: -- 1) Concurrent Signal Assigment -- 2) Proces Statement -- 3) Block Statement -- 4) Select Signal Assigment Statement -- 5) Component Instantiations Statement -- 6) Generate Statement -- 7) Concurrent Procedure Calls Statement -- BLOCK Concurrent Statement Syntax: -- -- [ <Label> : ] [ POSTPONED ] <Procedure Name> [ ( <Actual Parameter Part> ) ] ; -- -- -- Notes: -- Label : 语句标号 -- POSTPONED : (后置代码) -- Procedure Name : 过程名称 -- Actual Parameter Part : 实参表 -- ...... PROCEDURE adder ( SIGNAL a, b : IN STD_LOGIC ; SIGNAL sum : OUT STD_LOGIC ); ...... adder ( adder ( a1, b1, sum1 ); -- concurrent procedure call ...... PROCESS ( c1, c2 ) BEGIN ...... adder ( c1, c2, s1 ); -- sequential procedure call ...... END PROCESS;