NXP Semiconductors P89V51RB2FN,112

Overview

P89V51RB2FN,112 from NXP Semiconductors is an 8-bit 80C51 microcontroller in DIP40 package with 16 kB flash program memory, 1024 B on-chip RAM, and support for both 12-clock and 6-clock (X2) machine cycle modes. It operates from 0 MHz to 40 MHz at 5 V and integrates SPI, enhanced UART, PCA with PWM/capture/compare, three 16-bit timers, and programmable watchdog - used in industrial control panels requiring field firmware updates via ISP.

For engineers reviewing the P89V51RB2FN,112 datasheet, P89V51RB2FN,112 pinout, P89V51RB2FN,112 application, or P89V51RB2FN,112 equivalent, key selection considerations include X2 mode throughput doubling, IAP capability during runtime, brownout detection at 2.35 V, DIP40 through-hole compatibility for prototyping, and 16 mA high-current drive on Port 1 pins P1.5–P1.7.

Technical Context

The P89V51RB2FN,112 implements a standard 80C51 CPU core with dual clock mode selection (12 clocks or 6 clocks per machine cycle), enabling either doubled performance at same frequency or halved EMI by reducing clock frequency while maintaining throughput. Its flash memory supports parallel programming and serial ISP, with dedicated boot block (Block 1) for in-system firmware updates.

It features a Programmable Counter Array (PCA) with five capture/compare modules mapped to Port 1 pins, integrated SPI controller with master/slave operation, and dual DPTR register for efficient external memory access. Brownout detection triggers reset at 2.35 V, and low-power idle/power-down modes support interrupt wake-up.

Key Specifications

Pinout & Package

DIP40 plastic dual in-line package (600 mil width), through-hole mountable, compatible with standard 0.1″ pitch breadboards and PCB sockets. Pin count and layout conform to JEDEC MS-026AC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT89C51-24PU and STC89C52RC-PDIP40, the P89V51RB2FN,112 delivers verified industrial temperature operation, deterministic brownout reset at 2.35 V, and production-ready ISP/IAP - making it suitable for long-lifecycle equipment where firmware maintenance and reliability are mandatory.

Availability

P89V51RB2FN,112 is available at Aetrix Electronics and suitable for industrial control panels, embedded data loggers, legacy equipment retrofits, and education platforms requiring stable component supply and long-term manufacturability.

Supply support for P89V51RB2FN,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 leader focused on secure connectivity solutions for automotive, industrial, and IoT applications.

The P89V51RB2FN,112 belongs to NXP's legacy 80C51 microcontroller family, designed for cost-sensitive, high-reliability industrial control and retrofit applications requiring proven architecture, long-term support, and robust in-system programmability.

FAQ

What is the maximum operating frequency of the P89V51RB2FN,112?

The P89V51RB2FN,112 supports a maximum crystal frequency of 40 MHz across its full industrial temperature range (−40 °C to +85 °C). In X2 mode, this yields effective instruction throughput equivalent to an 80 MHz traditional 8051, while maintaining full electrical and timing compliance per the NXP datasheet Rev. 05.

Does the P89V51RB2FN,112 support in-application programming (IAP)?

Yes, the P89V51RB2FN,112 supports true IAP: flash memory can be reprogrammed while the main application continues executing. This requires configuring the flash bank select bits (BSEL/SWR in FCF register) and using the built-in IAP routines located in Block 1 - fully documented in the NXP P89V51RB2_RC2_RD2_5 datasheet section 6.2.1.

What package type is used for the P89V51RB2FN,112?

The P89V51RB2FN,112 uses a plastic dual in-line package with 40 leads (DIP40), 600 mil width, per ordering code SOT129-1. It is pin-compatible with standard 8051 DIP sockets and supports through-hole assembly, prototyping on solderless breadboards, and manual rework.

How does the X2 mode affect ALE frequency on the P89V51RB2FN,112?

In X2 mode, the ALE signal on the P89V51RB2FN,112 is emitted at one-third of the crystal frequency (not one-sixth as in default mode). This higher ALE rate supports faster external memory latching but increases EMI - the ALE inhibit function (AO bit) remains available to disable it entirely when needed.

Which pins on the P89V51RB2FN,112 support 16 mA drive current?

Port 1 pins P1.5 (MOSI/CEX2), P1.6 (MISO/CEX3), and P1.7 (SPICLK/CEX4) each support 16 mA sink/source capability on the P89V51RB2FN,112. This is explicitly specified in Table 3 of the NXP datasheet and enables direct driving of LEDs, small relays, or optocouplers without external buffer transistors.