AT89C51 Microcontroller IC

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K 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 and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications.

It works with the popular 8051 architecture and hence is used by most beginners till date. It has four ports and all together provide 32 Programmable GPIO pins. It does not have in-built ADC module and supports only USART communication. Although it can be interfaced with external ADC IC like the ADC084 or the ADC0808.

The AT89C51 is no longer in production and Atmel does not support new design. Instead, the new AT89S51 is recommended for new applications. But since the AT89C51 has a strong community support, if your motive is to learn embedded then AT89C51 can still be a good choice.

Features

• Compatible with MCS-51 ™ Products
• 4K Bytes of In-System Reprogrammable Flash Memory
• Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial Channel
• Low-power Idle and Power-down Modes

AT89C51 Datasheet