The AT89C2051 is a low‑voltage, high‑performance 8‑bit CMOS microcontroller with 2 Kbytes of flash memory, 128 bytes of RAM, 15 programmable I/O lines, two 16‑bit timer/counters, and a full‑duplex serial UART. It operates from 2.7 V to 6 V and can run at frequencies up to 24 MHz while supporting idle and power‑down power‑saving modes.
The document provides a complete pin description, oscillator characteristics, special function registers, programming algorithms, flash programming modes, and verification procedures. Ordering information for commercial, industrial, and automotive packages (PDIP and SOIC) is also included.
| Flash Memory | 2 Kbytes |
|---|---|
| RAM | 128 bytes |
| Programmable I/O Lines | 15 |
| Timer/Counters | Two 16‑bit |
| Operating Voltage | 2.7 V to 6 V |
| Maximum CPU Frequency | 24 MHz |
| Programming Enable Voltage (Vpp) | 11.5 V to 12.5 V |
The device operates from 2.7 V to 6 V.
It includes 2 Kbytes of flash programmable memory.
The microcontroller offers 15 programmable I/O lines.
Programming requires a Vpp of 11.5 V to 12.5 V.