always块是Verilog中的程序块之一。块内的语句总是按顺序执行。 语法 always @(event) [statement] always @ (event) begin [multiple statements] end always 块是在特定的事件触发下执行的,这些特定的事件被定义为敏感列表。 什么是敏感列表? 敏感列表是定义何时应执行alway
always @ (event) [statement] always @ (event) begin [multiple statements] end 1. 2. 3. 4. 5. 6. 第一种是块内只有一条语句,不需要使用begin end;第二种是有多条语法,需要使用begin end包裹起来。 这其实都是废话。我们推荐全部都用begin end包裹起来,这样形式比较固定,比较方面阅读以及形成固定风格。
verilog always语法 目前的两种用法: always @(*) always @(posedge clk) Build an XOR gate three ways, using an assign statement, a combinational always block, and a clocked always block. Note that the clocked always block produces a different circuit from the other two: There is a flip-flop...
verilogalways语法 verilogalways语法 ⽬前的两种⽤法：always @(*)always @(posedge clk)Build an XOR gate three ways, using an assign statement, a combinational always block, and a clocked always block. Note that the clocked always block produces a different circuit from the other two: There ...
1 always_comb always_comb相较原有的"always @(sig_lsit)"和"always@*"有以下几点不同: always_comb不用写敏感信号列表,不用担心其中存在函数调用时漏缺了其中的敏感信号; always_comb会在仿真开始的0时刻自动执行一次,可以有效的解决状态机跳转进入死循环的问题,可参见前文《Verilog系列:使用枚举类型表示状态...
当我尝试检查一个always块中的两个输入时，我得到了推断的闩锁警告，并且我的代码在Verilog中运行不一致...
b = a; // changing b does not re-trigger the always_comb in this time step end Conventional wisdom would be that both code examples should behave and execute the same way. However, that is not always the case! There is a clause in the SystemVerilog language manual that defines the imp...
Only an 'if' statement is allowed at the top level in this always block. (ELAB-302) 在《HDL Compiler for Verilog User Guide》中,有如下要求: The tool does not support more than one independent if block when asynchronousbehavior is modeled within an always block. If the always block is ...
In Verilog, the assign statement is used for combinatorial logic.4. always语句通常用于描述时序逻辑。The always statement is commonly used to describe sequential logic.5. assign语句可以在模块层次或过程内使用。The assign statement can be used at the module level or within a process.6. always语句...
if(condition1) true_statement1;elseif (condition2) true_statement2;elseif (condition3) true_statement3;elsedefault_statement ; 如果只有两种情况,就只有if和else。下面用上一节中MUX2_1做练习,上一节中采用了assign的三元运算符语句,这里使用always if语句实现2选1的功能: ...