NXP Semiconductors P80C31X2BN,112

Overview

P80C31X2BN,112 from Philips Semiconductors is a ROMless 8-bit microcontroller based on the enhanced 80C51 architecture, featuring 128-byte RAM, three 16-bit timers/counters (T0/T1/T2), full-duplex UART with framing error detection, and support for both 6-clock and 12-clock operation. It operates from 2.7 V to 5.5 V and delivers up to 33 MHz at 5 V in 12-clock mode, targeting embedded control in industrial instrumentation and legacy system upgrades.

For engineers reviewing the P80C31X2BN,112 datasheet, P80C31X2BN,112 pinout, P80C31X2BN,112 application, or P80C31X2BN,112 equivalent, key selection criteria include its DIP40 package compatibility with through-hole prototyping, zero-frequency static operation for ultra-low-power sleep modes, dual data pointer support for efficient external memory access, and hardware-assisted power-down wake-up via INT0/INT1.

Technical Context

This device implements a fully static CMOS 80C51 core with extended SFRs including T2CON, RCAP2H/L, and AUXR for Timer 2 capture/compare and clock-mode control. Its dual-clock architecture allows runtime switching between 6-clock (2× instruction throughput) and 12-clock (standard 8051 timing) via CKCON.X2 bit.

The microcontroller integrates a programmable clock-out function on P1.0 (T2), supports asynchronous port reset, and provides low-EMI features including ALE inhibit and slew-rate-controlled outputs-enabling reliable operation in electrically noisy environments without external filtering.

Key Specifications

Pinout & Package

Package: Plastic Dual In-Line Package (DIP40), 40-pin, 600 mil width, 0 °C to +70 °C operating temperature range (SOT129-1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT89C51-24PI and P87C51X2BN,112, the P80C31X2BN,112 offers unique ROMless flexibility for external boot loaders and eliminates Flash/OTP programming overhead, while retaining full T2 functionality and 6/12-clock runtime switching - critical for timing-sensitive legacy integration.

Availability

P80C31X2BN,112 is available at Aetrix Electronics and suitable for industrial control panels, legacy system upgrades, embedded data loggers, and power-metering interfaces requiring stable component supply and long-term obsolescence management.

Supply support for P80C31X2BN,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

Philips Semiconductors (now NXP Semiconductors) is a pioneer in high-reliability mixed-signal ICs, delivering automotive, industrial, and consumer solutions with emphasis on robustness and longevity.

The P80C31X2BN,112 belongs to the 80C51X2 family designed specifically for drop-in replacement of legacy MCS-51 systems, emphasizing pin compatibility, extended voltage range (2.7–5.5 V), and enhanced power management for industrial maintenance and retrofit applications.

FAQ

What is the maximum operating frequency of the P80C31X2BN,112?

The P80C31X2BN,112 supports up to 33 MHz in 12-clock mode and 30 MHz in 6-clock mode at 5 V ±10%. At lower supply voltages (2.7–5.5 V), the maximum frequency is limited to 16 MHz in both modes. The device's static CMOS design permits operation down to 0 Hz, enabling true zero-power idle states.

Does the P80C31X2BN,112 include on-chip program memory?

No, the P80C31X2BN,112 is a ROMless variant - it contains no on-chip program memory. Code execution must occur from external EPROM, Flash, or ROM via the P0/P2 address/data bus. This distinguishes it from OTP variants like P87C51X2BN,112 and enables flexible boot-loader architectures.

How does the P80C31X2BN,112 handle power-down wake-up?

The P80C31X2BN,112 supports wake-up from Power-down mode via external interrupt on INT0 (P3.2) or INT1 (P3.3), provided WUPD bit (AUXR1.3) is set and the interrupt is configured as level-sensitive. Upon wake-up, the oscillator restarts, and execution resumes from the instruction following the Power-down command - with RAM and SFRs fully preserved.

Can the P80C31X2BN,112 generate a clock signal for external peripherals?

Yes, the P80C31X2BN,112 can output a precise 50% duty-cycle clock on P1.0 (T2) using Timer 2 in clock-out mode. Frequencies range from 61 Hz to 4 MHz (at 16 MHz oscillator, 12-clock mode) and are programmable via RCAP2H/L registers - eliminating the need for external clock generators in synchronized sensor or display interfaces.

Is the P80C31X2BN,112 pin-compatible with standard 8051 microcontrollers?

Yes, the P80C31X2BN,112 uses the industry-standard DIP40 pinout matching the original 8031/8051, including identical placement of P0–P3, RST, XTAL1/XTAL2, EA/VPP, ALE, and PSEN. All port functions and timing parameters comply with MCS-51 specifications, enabling direct substitution in legacy designs without PCB changes.