The PD17P228 is a model of the PD17228 with a one-time PROM instead of an internal mask ROM. Since the user can write programs to the PD17P228, it is ideal for experimental production or small-scale production of the PD17225, 17226, 17227 or 17228 systems. When reading this document, also read the documents related to the PD17225, 17226, 17227 and 17228. Detailed functions are described in the following user's manual. Read this manual when designing your system.