The AT89C1051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 1K byte of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel's high density nonvolatile memory technology and is compatible with the industry standard MCS-51TM instruction set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C1051 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. The AT89C1051 provides the following standard features: 1K Byte of Flash, 64 bytes of RAM, 15 I/O lines, one 16-bit timer/counter, a three vector two-level interrupt architecture, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C1051 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.