absaccess after alias all and architecture array assert attribute begin block buffer bus case component configuraTIon constant disconnect downto else elsif end enTIty exit file for funcTIon generate generic group guarded if impure in inerTIal inout is label library linkage literal loop map mod nand new...
为避免错误地修改全局信号,不推荐用非内的参数来传递信息 在含有敏感信号表的进程中调用过程时,过程内部禁用wait语句 函数: 可以被看作是一个能和运算符一起参加运算的广义表达式,其功能可以通过 一组顺序语句来实现 pure|impure function () return is begin ; end function ;注:函数只允许形式参数为常量和信号...
信号与常数相当于全局变量,变量相当于局部变量,变量只能存在于PROCESS,FUNCTION,PROCEDUCE中。不能带出PROCESS,FUNCTION,PROCEDUCE,传送出去,而信号可以。1.3VHDL设计的基本语句VHDL常用语句可以分为两大类并行语句和顺序语句,在数字系统的设计中,这些语句用来描述系统的内部硬件结构和动作行为,以及信号之间的基本逻辑关系。
29、ATE NOR REPORT USE BEGIN GENERIC NOT RETURN VARIABLE BLOCK GROUP NULL ROL WAIT BODY GUARDED OF ROR WHEN BUFFER IF ON SELECT WHILE BUS IMPURE OPEN SEVERITY WITH CASE IN OR SIGNAL XNOR COMPONENT INERTIAL OTHERS SHARED XOR CONFIGURATION INOUT OUT SLA CONSTANT IS PACKAGE SLL DISCONNECT LABEL PO...
(3) task语句 task 语句是包含多个语句的子程序,主要作用是简化程序结构,增加程序的可读性.它 与函数的相同点在于可以接收参数,不同点在于它不返回值.定义格式如下: task 任务名; 端口和数据类型说明; 语句 1; 语句 2; … 语句 n; endtask; 调用格式如下: 任务名(端口 1,端口 2,…) (4) function(...
第244页/共348页 244 abs,access,after,alias,all,and,architecture,array, assert, attribute begin,block,body,buffer,bus case,component,configuration,constant disconnect,downto else,elsif,end,entity,exit file,for,function generate,generic,group,guarded if,impure,in,inertial,inout,is label,library,...
;3.4 VHDL顺序语句引言:VHDL主要描述语句 1、顺序语句:在进程(PROCESS)、函数(FUNCTION)、过程(PROCEDURE)中执行的语句;具有高级语言的特点。 2、并行语句: 在结构体(ARCHITECTURE)中执行的语句;具有硬件描述的特点。;进程(PROCESS)进程内所有语句都是顺序执行的;结构体中有多个进程时,各进程间为并行语句语法如下: ...
disconnect downto else elsif end entity exit file for function generate generic group guarded if impure in inertial inout is label library linkage literal loop map mod nand new next nor not null of on open or others out package port postponed procedure process pure range record register reject ...
10、architecture array assert attributebegin block buffer bus case component configuration constantdisconnect downto else elsif end entity exit file for functiongenerate generic group guarded if impure in inertial inoutis label library linkage literal loop map mod nand new next nornot null of on open...
DOWNTOELSEELSIFENDENTITYEXITFILEFORFUNCTIONGENERATEGENERICGROUPGUARDEDIFIMPUREININERTIALINOUTISLABELLIBRARYLINKAGELITERALLOOPMAPMODNANDNEWNEXTNORVHDL语言的语言要素863.标识符(5)保留字NOTNULLOFONOPENOROTHERSOUTPACKAGEPORTPOSTPONEDPROCEDUREPROCESSPURERANGERECOREGISTERRDREJECTREMREPORTRETURNROLRORSELECTSEVERITYSIGNALSHARED...