REX128128AYAP3N00000 is an OTP (One-Time Programmable) parts manufactured by Raystar. It is an 8-bit AVR microcontroller programmed with Fuse bits and lock bits. This part has 32 kB of flash memory and 2 kB of SRAM memory. It is capable of working with both 5 and 3.3 volts. This part also has five I/O ports that allow the user to connect different peripheral components to the microcontroller.