l level converter shown in FIG. 17A and FIG. 17B; FIG. 20 is a block diagram for explaining an example of a third judgment circuit for use in the logical level converter shown in FIG. 17A and FIG. 17B; FIG. 21 is a block diagram for explaining an example of a fourth judgment circuit for use in the logical level converter shown in FIG. 17A and FIG. 17B; FIG. 22 is a block diagram for explaining an