The 89C51RB2/RC2/RD2 is a derivative of the 80C51 microcontroller, manufactured using advanced CMOS technology. The instruction set is identical to the 80C51, with 4 groups of 8-bit I/O ports, 3 16-bit timers/counters, multiple interrupt sources, 4 interrupt priorities, nested interrupt structure, 1 enhanced UART, and on-chip oscillator and timing circuit. The new features make the 89C51RB2/RC2/RD2 a more powerful microcontroller that better supports applications such as pulse width modulation, high-speed I/O, increment/decrement counting, such as motor control, etc.
This manual provides an overview of the P89C51RB2/RC2/RD2 8‑bit microcontroller, its 16 KB/32 KB/64 KB parallel programmable flash, ISP and IAP programming methods, and the built‑in boot ROM that enables UART‑based code loading. It also details the device architecture, including the 80C51 core, instruction set compatibility, and the extended peripheral set.
The document covers pin descriptions, memory organization, timer/counter operation, PCA modules, UART features, power‑saving modes (idle, power‑down), and security (programmable lock bits). Ordering information, package options (PDIP, PLCC, LQFP) and electrical characteristics are also included. This manual is written in Chinese.
| Flash program memory | 16 KB / 32 KB / 64 KB parallel programmable |
|---|---|
| RAM | Up to 64 KB |
| I/O ports | 4 groups of 8‑bit I/O (32 pins) |
| Timers / Counters | 3 × 16‑bit timers/counters |
| UART | Full‑duplex enhanced UART with frame error detection |
The microcontroller provides four groups of 8‑bit I/O ports, for a total of 32 I/O pins.
It includes idle mode, power‑down mode, and a static stop mode where the clock can be halted to reduce power consumption.
In the 6‑clock‑cycle mode the MCU can run up to 20 MHz (effective 40 MHz internal rate).