The “Code” for a field will be triggered whenever you make an entry into the field, or edit the field. The entry can be from the data sheet or any data entry object in a form.
The “Procedure” for an object in a form is for the object, not the field it is associated with. If the object is a text editor object, it should not be set for Pop Up Editing, and you should check one of the boxes to tell it when the procedure should be triggered. An object’s procedure will run, even when it’s being used to set a variable.