The AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with2K bytes of Flash programmable and erasable read-only memory (PEROM). Thedevice is manufactured using Atmel’s high-density nonvolatile memory technologyand is compatible with the industry-standard MCS-51 instruction set. By combining aversatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C2051 is a powerfulmicrocomputer which provides a highly-flexible and cost-effective solution to manyembedded control applications.The AT89C2051 provides the following standard features: 2K bytes of Flash, 128bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interruptarchitecture, a full duplex serial port, a precision analog comparator, on-chip oscillatorand clock circuitry. In addition, the AT89C2051 is designed with static logic for operationdown to zero frequency and supports two software selectable power savingmodes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serialport and interrupt system to continue functioning. The power-down mode saves theRAM contents but freezes the oscillator disabling all other chip functions until the nexthardware reset