NXP Semiconductors MC68711E20CFUE3

Overview

MC68711E20CFUE3 from Freescale Semiconductor is an 8-bit HCMOS microcontroller in the M68HC11E family, featuring 512 bytes of on-chip EEPROM, 256 bytes of RAM, and a 10-bit A/D converter with 8 input channels. It operates at up to 3.0 MHz internal bus speed, supports single-chip and expanded modes, and integrates SCI, SPI, and timer subsystems. It targets embedded control in industrial sensors, motor controllers, and legacy automotive subsystems.

For engineers reviewing the MC68711E20CFUE3 datasheet, MC68711E20CFUE3 pinout, MC68711E20CFUE3 application, or MC68711E20CFUE3 equivalent, key selection criteria include EPROM programmability, 5 V operation, 40-pin QFP package compatibility, and bootstrap-mode firmware loading capability.

Technical Context

The MC68711E20CFUE3 implements the M68HC11 CPU core with full instruction set compatibility, including indexed, extended, and relative addressing modes. Its memory map includes 512-byte EEPROM (user-programmable), 256-byte RAM, and 2 KB of mask-programmed ROM containing monitor firmware.

It features a 10-bit successive-approximation A/D converter with software-selectable conversion time (8–16 µs), dual serial interfaces (SCI for UART-style communication and SPI for synchronous peripheral control), and a 16-bit timer system supporting input capture, output compare, and real-time interrupt generation.

Key Specifications

Pinout & Package

MC68711E20CFUE3 is housed in a 44-pin QFP (Quad Flat Package) with 0.8 mm lead pitch and exposed thermal pad. Pin assignments follow the M68HC11E family standard layout, supporting single-chip mode operation with integrated oscillator circuitry.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68711E20CFUE3, the MC68HC11E9CP removes ROM-based monitor functionality-reducing flexibility for remote updates-while the MC68HC11A8CP adds memory and precision at higher cost, making it appropriate for next-generation derivatives requiring scalability.

Availability

MC68711E20CFUE3 is available at Aetrix Electronics and suitable for industrial sensor nodes, legacy automotive ECUs, and motor control interfaces requiring stable component supply and long-term obsolescence management.

Supply support for MC68711E20CFUE3 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

Freescale Semiconductor (now part of NXP Semiconductors) was a leading designer of embedded processors, analog, and mixed-signal ICs for automotive, industrial, and networking markets.

The MC68711E20CFUE3 belongs to the M68HC11E family, engineered for cost-sensitive, low-power embedded control applications where deterministic real-time performance and in-system programmability are essential.

FAQ

What is the maximum operating frequency of the MC68711E20CFUE3?

The MC68711E20CFUE3 supports a maximum internal bus frequency of 3.0 MHz, derived from an external crystal (1–4 MHz) or clock source applied to the XTAL/EXTAL pins. This frequency governs instruction execution speed, A/D conversion timing, and serial baud rate generation. The device does not support internal PLL multiplication, so system timing is directly tied to the oscillator input.

Does the MC68711E20CFUE3 include a factory-programmed ROM monitor?

Yes, the MC68711E20CFUE3 contains 2 KB of mask-programmed ROM that implements a bootstrap monitor. This enables firmware loading via the SCI interface using standard terminal software - a key feature distinguishing it from variants like the MC68HC11E9CP. The monitor supports memory read/write, register inspection, and program execution control without external programming hardware.

Can the MC68711E20CFUE3 operate from a 3.3 V supply?

No, the MC68711E20CFUE3 is specified for 4.5 V to 5.5 V operation only. It is not compatible with 3.3 V logic families or supply rails. Attempting to power it below 4.5 V may result in undefined behavior, failed A/D conversions, or unreliable serial communication. For 3.3 V systems, consider later-generation HC11-compatible devices or level-shifting interface circuitry.

How many analog input channels does the A/D converter in the MC68711E20CFUE3 support?

The MC68711E20CFUE3 integrates a 10-bit successive-approximation A/D converter with eight single-ended analog input channels (AN0–AN7), mapped to Port E pins. Channel selection is software-controlled via the A/D control register, and conversion results are stored in two 8-bit result registers (ADR1 and ADR2) accessible through memory-mapped I/O.

Is the MC68711E20CFUE3 pin-compatible with other M68HC11E family members?

Yes, the MC68711E20CFUE3 uses the standard 44-pin QFP footprint shared across the M68HC11E family, including the MC68HC11E9CP and MC68HC11A8CP. Pin functions (e.g., PORTA0–7, SCI1/SCI0, E-clock) are identical, enabling direct PCB substitution where memory, timing, and feature requirements align - though firmware and configuration registers must be verified per variant.