If you want to know what books are on a shelf (reading data), you need to provide the category number to the administrator (input the address information through the address line), and the administrator can tell you what books are on the shelf in this category (the chip outputs data information through the data line).

If you want to return books or donate some books to the library (write materials), you need to provide the administrator with the category number (enter the address information through the address bar), tell the administrator what books to return/donate (write materials through the data cable), and the administrator will record them and put them on the designated bookshelf (the chip stores information).