NXP Semiconductors P89V51RD2FN,112

Overview

P89V51RD2FN,112 from NXP Semiconductors is an 8-bit 80C51 microcontroller with 64 kB on-chip flash program memory, 1 kB data RAM, 5 V operation up to 40 MHz, X2 mode (6-clock/machine cycle), and in-system programmability (ISP) and in-application programming (IAP). It serves as a main control unit in industrial embedded systems requiring field firmware updates and low-EMI timing.

For engineers reviewing the P89V51RD2FN,112 datasheet, P89V51RD2FN,112 pinout, P89V51RD2FN,112 application, or P89V51RD2FN,112 equivalent, key selection criteria include flash size (64 kB), DIP40 package compatibility, X2 mode throughput doubling, ISP/IAP capability, and brownout detection at 2.35 V.

Technical Context

The P89V51RD2FN,112 implements a standard 80C51 CPU core with dual clock modes: default 12-clock and selectable 6-clock (X2) mode via software or ISP, enabling either doubled performance at same frequency or halved clock for EMI reduction. Its memory architecture includes two flash blocks-Block 0 (64 kB user code) and Block 1 (IAP/ISP routines)-with bank selection controlled by SWR and BSEL bits in FCF register.

It integrates peripheral resources including SPI, enhanced UART, PCA with five capture/compare channels (CEX0–CEX4), three 16-bit timers/counters, programmable watchdog timer, and eight interrupt sources with four priority levels. Port 1 pins P1.5–P1.7 support 16 mA high-current drive and dual-function I/O for SPI and PCA.

Key Specifications

Pinout & Package

Package: DIP40 - plastic dual in-line package, 40-pin, 600 mil width, through-hole mounting compatible with standard 0.6-inch IC sockets.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with AT89C51ED2-RL24 and STC89C52RC-PD, the P89V51RD2FN,112 uniquely delivers 64 kB flash in DIP40 with full ISP/IAP, X2 mode, and industrial-grade brownout protection-making it optimal for long-lifecycle, field-serviceable 5 V control systems.

Availability

P89V51RD2FN,112 is available at Aetrix Electronics and suitable for industrial PLCs, legacy equipment upgrades, smart energy meters, and portable test instruments requiring stable component supply across multi-year production cycles.

Supply support for P89V51RD2FN,112 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The P89V51RD2FN,112 belongs to NXP's legacy 80C51 microcontroller family, designed specifically for industrial control, instrumentation, and upgrade paths from classic MCS-51 systems-emphasizing reliability, in-field programmability, and long-term availability.

FAQ

What is the maximum operating frequency of the P89V51RD2FN,112?

The P89V51RD2FN,112 operates from 0 MHz to 40 MHz at 5 V. In X2 mode, it achieves twice the instruction throughput per MHz versus standard 80C51-so at 20 MHz it matches the performance of a 40 MHz conventional 80C51. The datasheet specifies 40 MHz as the absolute maximum crystal frequency for stable operation across the full −40 °C to +85 °C temperature range.

Does the P89V51RD2FN,112 support in-system programming (ISP) and in-application programming (IAP)?

Yes, the P89V51RD2FN,112 fully supports both ISP and IAP. ISP allows reprogramming via UART using the built-in bootloader without removing the device from the circuit. IAP enables the running application to erase and rewrite flash sectors-including updating its own code-by calling the on-chip IAP routines located in Block 1, subject to proper bank selection (BSEL/SWR bit configuration).

What package type and pin count does the P89V51RD2FN,112 use?

The P89V51RD2FN,112 uses a DIP40 (dual in-line package) with 40 leads and 600 mil body width. This through-hole package is compatible with standard 0.6-inch IC sockets and prototyping breadboards, and matches the pinout of legacy 8051-family DIP40 MCUs for drop-in replacement in existing designs.

How does the X2 mode affect power consumption and EMI in the P89V51RD2FN,112?

In X2 mode, the P89V51RD2FN,112 executes instructions in six clock cycles instead of twelve, allowing the same performance at half the crystal frequency-e.g., 20 MHz crystal delivers 40 MHz-equivalent throughput. This directly reduces dynamic power (P ∝ f × V²) and radiated EMI amplitude, which scales with fundamental frequency and harmonics. ALE is also emitted at 1/3 crystal frequency in X2 mode, further lowering noise.

What is the brownout detection threshold and behavior for the P89V51RD2FN,112?

The P89V51RD2FN,112 features a fixed brownout detection threshold of 2.35 V. When VDD drops below this level, the device generates a brownout interrupt (if enabled via EBO bit) or forces a hardware reset. The reset clears the BSEL bit but preserves SWR state, ensuring predictable flash banking after recovery. Brownout detection remains active during Power-down and Idle modes, protecting against code corruption during supply instability.