case_item1 : <single statement> case_item2, case_item3 : <single statement> case_item4 : begin <multiple statements> end default : <statement> endcase 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 如果所有的case项都不符合给定的表达式,则执行缺省项内的语句,缺省语句是可选的,在case语句中只能...
modulemy_mux(input[2:0]a,b,c,// Three 3-bit inputs [1:0] sel, // 2-bit select signal to choose from a, b, c output reg [2:0] out); // Output 3-bit signal // This always block is executed whenever a, b, c or sel changes in valuealways @(a,b,c,sel)begincase(sel...
A single bit multiplexer will have one control line two inputs ( say X and Y) and one output ( say Z). When the control is 0, X is connected to Z. When the Control is 1, Y is connected to Z. The figure below explains this Let write this example using verilog case statement ...
If the case statement in design has x and z in the case item alternatives, the results would be quite different. modulemy_mux(input[2:0]a,b,c,[1:0]sel,outputreg[2:0]out);// Case items have x and z and sel has to match the exact value for// output to be assigned with the...
“full_case parallel_case”, the Evil Twins of Verilog Synthesis Quiz and Sample Source Code Now it’s time for a quiz! How will each of the following variations of case statement behave when the case expression matches one of the non-default case items ...
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When "// synopsys full_case" is added to a case statement header, there is no change in the Verilog simulation for the case statement, since "// synopsys ..." is interpreted to be nothing more than a Verilog comment; however, Synopsys parses all Verilog comments that start with "// ...
We use a second if statement to model the behaviour of the multiplexor circuit. This is an example of a nested if statement in verilog. When the addr signal is 0b, we assign the output of the flip flop to input a. We use the first branch of the nested if statement to capture this...
I'm a beginner for verilog design. I have a question. Is there any way that could express a case statement in for loop including default part? I tried the code below. /// (reg [2:0] ctrl) for(i=0 ; i<5; i=i\+1) begin case(ctrl) i : begin out <= i; end endcase end...
一个由多个语句组成的块必须分组,并且位于begin和end之间。 // Here 'expression' should match one of the items (item 1,2,3,or 4) case(<expression>) case_item1: <single statement> case_item2: case_item3: <single statement> case_item4: begin <multiple statement> end default: <single stat...