a logic u201c high u201d level in response to the second inverted input signal in 2 b having a logic u201c low u201d level the fourth pull down signal pd 4 may be disabled to have a logic u201c low u201d level since the fourth control signal cnt 4 has a logic u201c high u201d level although both the fifth and sixth pull up elements p 14 and p 15 are turned on by the third pull up signal pu 3 enabled to have a logic u201c low u201d level the third pull up drive control element p 16 may be turned off by the fourth control signal cnt 4 having a logic u201c high u201d level thus the sixth pull up element p 15 cannot pull up a level of the first i o line gio 1 of the first i o line driver gio_drv 1 further although both the seventh and eighth pull up elements p 24 and p 25 are turned on by the fourth pull up signal pu 4 enabled to have a logic u201c low u201d level the fourth pull up drive control element p 26 may be turned off by the third control signal cnt 3 having a logic u201c high u201d level thus the eighth pull up element p 25 cannot pull up a level of the second i o line gio.