Verilog Processes


Verilog and SystemVerilog always constructs without an event control statement at the top cannot be synthesized. Additionally, they would activate in random order at the moment 0 at the beginning of a simulation.

Sigasi Visual HDL warns about always blocks without an event control statement at the start.

A good way to correct this description is to place the timing control statement at the top.

module test(clk, data_in, data_out);
    input clk;
    input[3:0] data_in;
    output reg[3:0] data_out;
    
    always
    begin
        data_out <= data_in;
        @(posedge clk); // Timing control not at the top of 'always'
    end
endmodule

module test(clk, data_in, data_out);
    input clk;
    input[3:0] data_in;
    output reg[3:0] data_out;
    
    always @(posedge clk)
       data_out <= data_in;
    
endmodule

Rule configuration

This rule can be disabled for your project, or its severity and parameters can be modified in the project linting settings. Alternatively, it can be manually configured with the following template:

27/severity/${path}={error|warning|info|ignore}