20'd0: instruction <= 32'h2011fffe; //     addi    $s1,    $zero,  2
20'd1: instruction <= 32'h00000000;
20'd2: instruction <= 32'h00000000;
20'd3: instruction <= 32'h00000000;
20'd4: instruction <= 32'h00000000; // start:
20'd5: instruction <= 32'h22310001; //     addi    $s1,    $s1,    -1
20'd6: instruction <= 32'h00000000;
20'd7: instruction <= 32'h00000000;
20'd8: instruction <= 32'h00000000;
20'd9: instruction <= 32'h00000000;
20'd10: instruction <= 32'h0620fffa; //     bgtz    $s1,    start
20'd11: instruction <= 32'h00000000;
20'd12: instruction <= 32'h00000000;
20'd13: instruction <= 32'h00000000;
20'd14: instruction <= 32'h00000000; // end:
20'd15: instruction <= 32'h0800000f; //     j       end