module piso4 (
input CLK,
input RST,
input LOAD,
input [3:0] D,
output reg serial_out
);
// Write your code here
reg [3:0] int_reg;
always @( posedge CLK , posedge LOAD )
begin
if( RST )
begin
serial_out <= 1'b0;
int_reg <= 4'd0;
end
else begin
if( LOAD )
begin
int_reg <= D;
end
else
begin
serial_out <= int_reg[0];
int_reg <= { 1'b0, int_reg[3:1]};
end
end
end
endmodule