NXP Semiconductors MC68HC711E20CFN3

Overview

MC68HC711E20CFN3 from Freescale Semiconductor is an 8-bit CMOS microcontroller in the M68HC11E family, featuring 20 kB on-chip EPROM, 512 bytes RAM, and integrated A/D converter, SCI, SPI, and timer subsystems. It operates at up to 3.2 MHz internal bus speed in single-chip mode and supports automotive, industrial control, and embedded instrumentation applications requiring nonvolatile program storage and analog interface capability.

For engineers reviewing the MC68HC711E20CFN3 datasheet, MC68HC711E20CFN3 pinout, MC68HC711E20CFN3 application, or MC68HC711E20CFN3 equivalent, key selection criteria include EPROM size (20 kB), 8-channel 8-bit A/D resolution, single-chip mode operation, 40-pin ceramic DIP package, and compatibility with HC11 assembly toolchains and legacy bootstrap programming.

Technical Context

The MC68HC711E20CFN3 implements the M68HC11 CPU core with full instruction set compatibility to the Motorola 6800 architecture, supporting indexed, extended, and inherent addressing modes. Its memory map includes 20 kB of user-programmable EPROM, 512 bytes of static RAM, and 256 bytes of I/O register space mapped into the same address space.

On-chip peripherals include an 8-channel 8-bit successive-approximation A/D converter with programmable conversion sequence, full-duplex asynchronous SCI with baud rate generator and wakeup capability, synchronous SPI master/slave interface, and a 16-bit timer system with input capture, output compare, and real-time interrupt functions.

Key Specifications

Pinout & Package

MC68HC711E20CFN3 is housed in a 40-pin ceramic dual in-line package (CERDIP) with 0.6-inch body width and 0.1-inch pin pitch, rated for industrial temperature range (–40°C to +85°C) and suitable for high-reliability applications including automotive engine control modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC711E20CFN3, the MC68HC11E9CP offers reduced memory and no in-system EPROM programming, while the MC68HC11F1CFN adds CAN and FLASH but requires PCB redesign due to different package and pin count - making MC68HC711E20CFN3 optimal for legacy EPROM-based, single-chip, 40-pin DIP designs.

Availability

MC68HC711E20CFN3 is available at Aetrix Electronics and suitable for automotive engine control units, industrial temperature controllers, legacy PLC I/O modules, and embedded data loggers requiring stable component supply and long-term obsolescence management.

Supply support for MC68HC711E20CFN3 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 communications markets.

The M68HC11E family, including MC68HC711E20CFN3, was engineered for cost-effective, reliable control in resource-constrained embedded systems where deterministic real-time response and on-chip analog integration were critical.

FAQ

What is the maximum operating frequency of the MC68HC711E20CFN3?

The MC68HC711E20CFN3 supports a maximum internal bus frequency of 3.2 MHz in single-chip mode, corresponding to an E-clock output of 3.2 MHz. This is achieved with a 4 MHz crystal (divided by 2 internally) or direct 3.2 MHz external clock applied to EXTAL. Higher frequencies risk timing violations in internal peripheral access and A/D conversion.

Does the MC68HC711E20CFN3 support in-system programming of its EPROM?

Yes, the MC68HC711E20CFN3 supports in-system EPROM programming using the XIRQ/VPPE pin to apply 12.5 V programming voltage. The on-chip EPROM programming control register (PROG) and bootstrap loader enable field updates without removing the device from the circuit, provided proper high-voltage generation and timing sequences are followed per the datasheet.

What are the A/D reference voltage options for the MC68HC711E20CFN3?

The MC68HC711E20CFN3 supports three A/D reference configurations: internal 1.25 V bandgap reference, external reference applied to VRH and VRL pins, or ratiometric reference using VDD as both supply and reference. Selection is controlled by bits in the OPTION register, allowing flexible measurement schemes for thermistors, potentiometers, or precision sensors.

Can the MC68HC711E20CFN3 operate in low-power modes, and what are their characteristics?

Yes, the MC68HC711E20CFN3 supports Wait and Stop modes. In Wait mode, the CPU halts but peripherals remain active; typical current is 10 mA. In Stop mode, the oscillator stops and only RTI wakeup or external interrupt can resume operation; typical current drops to 50 μA. Both modes retain RAM and register contents, enabling rapid resumption of real-time tasks.

Is the MC68HC711E20CFN3 pin-compatible with other M68HC11E family members?

The MC68HC711E20CFN3 is pin-compatible with other 40-pin DIP variants in the M68HC11E family, including the MC68HC11E9CP and MC68HC11E20CP, sharing identical pin assignments for power, clock, reset, interrupts, and all five I/O ports. Differences lie in memory size and EPROM programming capability-not physical layout-enabling drop-in replacement where firmware and voltage requirements align.