When the Switch is touched the first time, it starts flashing. It is now waiting for further input. When the Switch is touched a second time while flashing (input wait state), the specified bit turns ON. This is useful in preventing accidental input.
If the Switch is not touched a second time while flashing (input wait state), the specified bit will not turn ON.
Also, if another Switch is pressed during the wait state, the wait state ends and the specified bit does not turn ON.
10.10.1 Procedure - Confirming Before Turning a Switch ON (Double Touch)