A primary goal of SystemVerilog is to enable modeling large, complex designs more concisely than was possible with Verilog. This chapter presented enhancements to the procedural statements in Verilog that help to achieve that goal. New operators, enhanced for loops, bottom-testing loops, and unique...
//* Behavional is used when cicruit is sequential circuit it contain procedural statements *// module dflip_flop_bh (q, d_in, clk_in); input d_in, clk_in; / input variable of d flip flop is defined output reg q; / output variable of the d flip flop is defined always @ (posed...
Build a 2-to-1 mux that chooses between a and b. Choose b ifbothsel_b1 and sel_b2 are true. Otherwise, choose a. Do the same twice, once using assign statements and once using a procedural if statement. 构建一个在a和b之间进行选择的2对1 mux。如果sel_b1和sel_b2都为true,则选择b。
// 1-bit reg that is also an output port (this is still a vector) input wire [3:-2] z...
"things" are assign statements,// module instantiations, net/variable declarations, and procedural ...
Declarations_and_Statements ;endmodule 端口类型有 3 种: 输入(input),输出(output)和双向端口(inout)。 input、inout 类型不能声明为 reg 数据类型,因为 reg 类型是用于保存数值的,而输入端口只能反映与其相连的外部信号的变化,不能保存这些信号的值。
跟C一样, Verilog区分大小写并且有一个基本的预处理(虽然比ANSI C/C++复杂度小很多). 它的流控关键词 (if/else, for, while, case, etc.) 是相当的,它的运算优先级与C兼容. 句法的差异表现在: required bit-widths for variable declarations, demarcation of procedural blocks (Verilog uses begin/end ...
Chapter 7shows how to use the enhancements to Verilog operators and procedural statements to code accurate and deterministic hardware models, using fewer lines of code compared to standard Verilog. Chapter 8provides guidelines on how to use enumerated types and specialized procedural blocks for modeling...
Verilog always block is one of the four procedural statements in the original Verilog language. It can be used to model testbench stimulus as well as hardware design. The Verilog always block is essentially an infinite loop. However, when combined with a Verilog event expression, it can be us...
4'b1000, 4'b1001 , 4'b1010, 4'b1011 , 4'b1100 , 4'b1101, 4'b1110 , 4'b1111 : begin pcode = 3'b100; end The boolean-expr is evaluated and if it is true, the list of the procedural statements between begin and end is executed. If the boolean-expr is false the ...