NXP Semiconductors P87C52X2FN,112

Overview

P87C52X2FN,112 from NXP Semiconductors (formerly Philips) is an 8-bit OTP-based microcontroller in the enhanced 80C51 family, featuring 8 KB on-chip OTP ROM, 256 B 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 up to 33 MHz at 5 V. It operates across industrial temperature range (–40 °C to +85 °C) in a 40-pin DIP package and is used in legacy industrial control, sensor interface, and embedded instrumentation systems requiring ROM security and low-power static operation.

For engineers reviewing the P87C52X2FN,112 datasheet, P87C52X2FN,112 pinout, P87C52X2FN,112 application, or P87C52X2FN,112 equivalent, key selection considerations include OTP memory size (8 KB), dual clock mode configurability (6/12-clk), power-down/idle mode behavior, T2 capture/compare capability, and DIP-40 packaging with verified pin mapping for legacy board compatibility.

Technical Context

This device implements a static CMOS 80C51 core with extended SFRs including T2CON, RCAP2H/L, and AUXR/AUXR1 for Timer 2 control and low-power configuration. It supports two software-selectable clock modes: 12-clock (default reset state) and 6-clock (via CKCON.X2 bit or OTP OX2 bit), enabling runtime performance scaling without hardware change.

The architecture includes a Boolean processor, dual data pointers, four priority-level nested interrupts (six sources), and programmable clock-out on P1.0 derived from Timer 2 - all operating within 2.7–5.5 V supply range. Its static design permits zero-frequency operation and reliable wake-up from Power-Down via INT0/INT1 when WUPD is enabled.

Key Specifications

Pinout & Package

Package: Plastic Dual In-Line Package (DIP-40), 600 mil width, SOT129-1, industrial temperature range (–40 °C to +85 °C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with P80C52X2FN,112 and P87C54X2FN,112, the P87C52X2FN,112 offers optimal balance of field-programmable security (OTP), industrial temperature resilience, and legacy DIP-40 compatibility - making it the preferred choice for mid-volume, long-lifecycle embedded systems where firmware updates are infrequent but essential.

Availability

P87C52X2FN,112 is available at Aetrix Electronics and suitable for industrial control, sensor interface, and embedded instrumentation applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant through-hole manufacturing.

Supply support for P87C52X2FN,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 (originally Philips Semiconductors) is a global leader in high-reliability microcontrollers, automotive ICs, and secure connectivity solutions, with deep heritage in 8-bit embedded control.

The P87C5xX2 family was designed specifically for industrial and instrumentation applications demanding OTP security, wide voltage operation (2.7–5.5 V), and proven 80C51 software compatibility - enabling seamless migration from legacy MCS-51 platforms.

FAQ

What is the maximum operating frequency of the P87C52X2FN,112 and how does clock mode affect it?

The P87C52X2FN,112 supports up to 33 MHz in 12-clock mode and 30 MHz in 6-clock mode at 5 V ±10%. At wider supply ranges (2.7–5.5 V), max frequency is limited to 16 MHz in both modes. The CKCON.X2 bit or OTP OX2 bit selects the mode; 6-clock mode doubles instruction throughput but increases EMI, while 12-clock mode improves noise immunity and reduces power at same frequency. The P87C52X2FN,112 defaults to 12-clock mode after reset.

Does the P87C52X2FN,112 support in-system programming or field firmware updates?

No, the P87C52X2FN,112 uses one-time-programmable (OTP) ROM, which can only be programmed once using a parallel programmer - not in-circuit. Firmware updates require physical device replacement. For field-upgradable alternatives, consider flash-based successors like the NXP P89V51RD2, but note these are not pin-compatible with the P87C52X2FN,112.

How is the P87C52X2FN,112's Timer 2 different from Timers 0 and 1?

Timer 2 in the P87C52X2FN,112 adds capture, compare, auto-reload, and programmable clock-out capabilities beyond standard 80C51 Timers 0 and 1. It uses RCAP2H/L registers for reload values and supports high-resolution event timing (e.g., PWM edge detection). Unlike T0/T1, T2 can generate a clean 50% duty-cycle clock on P1.0 - a feature unavailable on earlier 8051 variants. This makes the P87C52X2FN,112 uniquely suited for synchronous peripheral interfacing.

Can the P87C52X2FN,112 operate reliably at 3.3 V, and what are the implications?

Yes, the P87C52X2FN,112 is specified for 2.7–5.5 V operation. At 3.3 V, maximum clock frequency drops to 16 MHz in both 6- and 12-clock modes. All I/O pins remain TTL/CMOS compatible, and internal regulators ensure stable SFR and RAM operation. However, the LPEP bit (AUXR.4) should be set to reduce analog circuit current draw - a documented optimization for sub-4 V supplies that directly lowers active power consumption in the P87C52X2FN,112.

What are the power-down wake-up sources for the P87C52X2FN,112, and how is wake-up configured?

The P87C52X2FN,112 supports wake-up from Power-Down mode via hardware reset or external interrupts on INT0 (P3.2) or INT1 (P3.3), provided WUPD (AUXR1.3) is set to 1. Level-sensitive configuration is mandatory: the interrupt pin must be held low to restart the oscillator, then brought high to complete wake-up and enter the ISR. Reset restores SFRs but preserves RAM; interrupt wake-up preserves both RAM and SFRs - a critical distinction for stateful applications using the P87C52X2FN,112.