Verilog Duplicate Conditions

Duplicate conditions decrease readability and could lead to unused code. Duplicate conditions are often an unintended result of copy-pasting. Sigasi marks these duplicates as warnings (rule 98).

module bad_code(input clk);
    if(clk && clk) begin
        // Do something
    end
endmodule

module good_code(input clk);
    if(clk) begin
        // Do something
    end
endmodule

This is also the case for if-else chains or switch cases.

module bad_code(input clk);
    if(clk) begin
        // Do something
    end else if(clk) begin
        // Never called
    end

    typedef enum {INIT, IDLE, START, READY} t_state;
    t_state state;

    always @(posedge clk) begin
        case (state)
            IDLE    : state = START;
            IDLE    : state = READY; // Never called
            READY   : state = IDLE ;
        endcase
    end
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:

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