88. Parallel-In Serial-Out Register

How do you plan to solve it?

module piso4 (
    input        CLK,
    input        RST,
    input        LOAD,
    input  [3:0] D,
    output reg   serial_out
);
    // Write your code here
    reg [3:0] t;
    always @(posedge CLK or posedge RST)
        if(RST) begin serial_out<=0; t<=0; end
        else if(LOAD) t<=D;
        else begin serial_out<=t[0]; t<={1'b0,t[3:1]}; end
    
endmodule