NXP Semiconductors MC68HC711E20CFN4

Overview

MC68HC711E20CFN4 from Freescale Semiconductor is an 8-bit microcontroller in the M68HC11E family, featuring 20 KB of on-chip EPROM, 512 bytes of RAM, and integrated peripherals including a 8-channel 8-bit ADC, SCI, SPI, and a 16-bit timer system. It operates at up to 2 MHz internal bus speed with single-chip mode execution and supports automotive and industrial control applications requiring deterministic real-time response.

For engineers reviewing the MC68HC711E20CFN4 datasheet, MC68HC711E20CFN4 pinout, MC68HC711E20CFN4 application, or MC68HC711E20CFN4 equivalent, this page delivers verified technical context, package mapping, functional specifications, and validated alternative options for legacy design support and component continuity planning.

Technical Context

The MC68HC711E20CFN4 implements the M68HC11 CPU core with Harvard architecture memory organization, supporting both single-chip and expanded bus modes. Its on-chip EPROM is factory-programmed and supports in-system reprogramming via bootstrap mode using external serial download.

It integrates a 16-bit timer subsystem with four input capture channels and three output compare channels, plus a real-time interrupt (RTI) module with programmable prescaler. The ADC features 8 multiplexed inputs, software-selectable conversion time, and result registers accessible via memory-mapped I/O.

Key Specifications

Pinout & Package

MC68HC711E20CFN4 is housed in an 84-pin Ceramic Flatpack (CFP) package with 0.050" lead pitch and ceramic-glass hermetic seal, designed for extended temperature operation and radiation-tolerant applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC711E20CFN4, the MC68HC11E9CFN2 offers reduced memory for cost-constrained designs, while the MC68HC11A8CP trades reprogrammability for OTPROM reliability and lower unit cost - both require identical PCB layout but differ in firmware update capability and memory scalability.

Availability

MC68HC711E20CFN4 is available at Aetrix Electronics and suitable for automotive engine control, industrial PLC modules, and medical infusion pump designs requiring stable component supply across long product lifecycles.

Supply support for MC68HC711E20CFN4 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 and analog/mixed-signal ICs, known for automotive, industrial, and networking solutions.

The M68HC11E family was engineered for deterministic real-time control in safety-critical and resource-constrained environments, emphasizing low-latency interrupt response, on-chip memory integration, and robust industrial packaging.

FAQ

What is the maximum operating frequency of the MC68HC711E20CFN4?

The MC68HC711E20CFN4 operates with a maximum internal bus frequency of 2 MHz, derived from an external crystal or clock source ranging from 1 MHz to 4 MHz. Its E-clock output runs at half the bus frequency (1 MHz max), and all internal timing-including ADC conversion and timer increments-is synchronized to this bus clock. This frequency limit ensures stable operation under worst-case voltage and temperature conditions as specified in the DC electrical characteristics table.

Does the MC68HC711E20CFN4 support in-system programming?

Yes, the MC68HC711E20CFN4 supports in-system programming via its built-in bootstrap monitor, which activates upon power-up when MODA and MODB pins are held low. Using the SCI interface and PCBUG11 host software, users can download and program the 20 KB EPROM without removing the device from the circuit board. This capability enables field firmware updates and eliminates the need for external EPROM programmers during development and maintenance.

What is the function of the VPPE pin on the MC68HC711E20CFN4?

The VPPE (V_PP Enable) function is multiplexed with the XIRQ pin on the MC68HC711E20CFN4. During normal operation, it serves as a non-maskable interrupt input. During EPROM programming cycles initiated via bootstrap mode, the same pin asserts V_PP (programming voltage enable) to activate the internal high-voltage generator required for EPROM cell programming. This dual-role design conserves pins while maintaining full programming functionality.

Can the MC68HC711E20CFN4 operate in expanded bus mode?

No, the MC68HC711E20CFN4 is configured exclusively for single-chip mode operation. Unlike some members of the M68HC11E family (e.g., MC68HC11E20), it lacks the necessary address/data bus pins and external memory control signals (e.g., AS, R/W, BA) to support expanded mode. Its memory map is fixed: 20 KB EPROM occupies $C000–$FFFF, and 512 bytes RAM resides at $0000–$01FF - all accessed internally without external bus cycles.

Is there a drop-in replacement for the MC68HC711E20CFN4 with higher memory capacity?

No verified drop-in replacement exists for the MC68HC711E20CFN4 with higher memory capacity in the same 84-pin CFP package and pinout. Later M68HC11 variants (e.g., MC68HC11K4) offer more memory but use different packages (PLCC, QFP) and incompatible pin assignments. Migration requires PCB redesign and firmware adaptation. For continuity, Aetrix recommends inventory planning and controlled obsolescence management rather than direct substitution.