Atmel's AT89C4051 is low-voltage, high-performance CMOS 8-bit microcontroller with 4KB of flash programmable and erasable read-only memory (PEROM). The device uses Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. This versatile 8-bit CPU with flash provides a highly-flexible and cost-effective solution for many embedded control applications.
The AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 2K bytes 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-51 instruction set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C2051 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded 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 interrupt architecture, a full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C2051 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.
This is a 10Mhz Crystal Oscillator HC49/US Package. The crystal oscillator is used in microprocessor clock, network card, various consumer electronics, etc.
