The DS2502 is EPROM. This kind of component can only change the internal register from 1 to 0, but not vice versa; as a result, the DS2502 is usually viewed as a one-time programmable product. If you would like to continue to use this product, please use the product's internal redirection function. In regards how to use this function, please refer to the data sheet's description under "EPROM STATUS BYTES".