The AT89C55WD-24JU is a low-power, high-performance 8-bit CMOS Microcontroller with 20kB of flash programmable read only memory and 256byte of RAM. The device is manufactured using high-density nonvolatile memory technology and is compatible with the industry standard 80C51 and 80C52 instruction set and pin out. The on-chip flash allows the program memory to be user programmed by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with flash on a monolithic chip, the AT89C55WD is a powerful microcomputer which provides a highly flexible solution.