module gpio_concat
(
    output  wire    [19:0]  gpio,
    
    input   wire            btn_0_down,
    input   wire            btn_1_down,
    input   wire            btn_2_down,
    input   wire            btn_3_down,
    
    input   wire            btn_0_up,
    input   wire            btn_1_up,
    input   wire            btn_2_up,
    input   wire            btn_3_up,
    
    input   wire            btn_0_shrt,
    input   wire            btn_1_shrt,
    input   wire            btn_2_shrt,
    input   wire            btn_3_shrt,
    
    input   wire            btn_0_long,
    input   wire            btn_1_long,
    input   wire            btn_2_long,
    input   wire            btn_3_long,
    
    input   wire            btn_0_imm,
    input   wire            btn_1_imm,
    input   wire            btn_2_imm,
    input   wire            btn_3_imm
);
    
    assign  gpio[0]  = btn_0_down;
    assign  gpio[1]  = btn_1_down;
    assign  gpio[2]  = btn_2_down;
    assign  gpio[3]  = btn_3_down;
    
    assign  gpio[4]  = btn_0_up;
    assign  gpio[5]  = btn_1_up;
    assign  gpio[6]  = btn_2_up;
    assign  gpio[7]  = btn_3_up;
    
    assign  gpio[8]  = btn_0_shrt;
    assign  gpio[9]  = btn_1_shrt;
    assign  gpio[10] = btn_2_shrt;
    assign  gpio[11] = btn_3_shrt;
    
    assign  gpio[12] = btn_0_long;
    assign  gpio[13] = btn_1_long;
    assign  gpio[14] = btn_2_long;
    assign  gpio[15] = btn_3_long;
    
    assign  gpio[16] = btn_0_imm;
    assign  gpio[17] = btn_1_imm;
    assign  gpio[18] = btn_2_imm;
    assign  gpio[19] = btn_3_imm;
    
endmodule