1Line cookie sheet with waxed paper. In large microwavable bowl, mix cereals and sweet potato chips.
2In 2-cup microwavable measuring cup, microwave butter, brown sugar, corn syrup and 1/2 teaspoon salt uncovered on High 1 minute 30 seconds. Stir; microwave on High about 45 seconds or until bubbling. Pour over cereal mixture; stir until completely coated.
3Microwave uncovered on High 3 to 4 minutes, stirring after every minute. Spread on cookie sheet. Let cool about 5 minutes or until coating hardens, stirring after first 2 minutes. Stir in marshmallows; sprinkle with remaining 1/2 teaspoon salt.