NXP Semiconductors MC68HC11F1CPU4

Overview

MC68HC11F1CPU4 from Freescale Semiconductor is an 8-bit microcontroller unit (MCU) with on-chip 512 B RAM, 2 KB EEPROM, and 12 KB ROM, operating at up to 4 MHz E-clock in single-chip mode. It integrates a serial communications interface (SCI), serial peripheral interface (SPI), 16-bit timer system with input capture/output compare, and an 8-channel 8-bit analog-to-digital converter - used in automotive body control modules and industrial sensor interfaces.

For engineers reviewing the MC68HC11F1CPU4 datasheet, MC68HC11F1CPU4 pinout, MC68HC11F1CPU4 application, or MC68HC11F1CPU4 equivalent, key selection criteria include its 68-pin PLCC package, single-chip vs. expanded mode flexibility, COP watchdog, real-time interrupt capability, and EEPROM reprogrammability without external hardware.

Technical Context

The MC68HC11F1CPU4 implements the HC11 CPU core with full instruction set compatibility to the Motorola 6800, supporting seven addressing modes including indexed and extended. Its memory architecture includes configurable chip selects for external expansion and dual-mode operation (single-chip/expanded), enabling use in both embedded controllers with minimal external components and systems requiring external memory or peripherals.

On-chip peripherals are tightly coupled to the CPU via dedicated I/O registers mapped into the memory space: the SCI supports asynchronous full-duplex communication with baud rate generation and wakeup features; the SPI operates in master/slave mode with programmable clock polarity and phase; and the A/D converter provides software-triggered or timer-triggered conversions with channel sequencing.

Key Specifications

Pinout & Package

MC68HC11F1CPU4 is housed in a 68-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead configuration, lead pitch of 0.05 inches (1.27 mm), and body size 1.100 × 1.100 inches (27.94 × 27.94 mm). The package supports surface-mount assembly and offers thermal performance suitable for industrial ambient temperatures (–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 MC68HC11E9CP2 and MC9RS08KA2CSC, the MC68HC11F1CPU4 uniquely balances EEPROM-based field updateability, COP safety enforcement, and dual serial interface support in a compact 68-pin PLCC - making it optimal for retrofit industrial controllers and automotive subsystems requiring proven reliability over 20+ years.

Availability

MC68HC11F1CPU4 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, appliance motor control, and legacy PLC I/O modules requiring stable component supply across long-lifecycle programs.

Supply support for MC68HC11F1CPU4 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 was a U.S.-based semiconductor company specializing in embedded processors, analog, and power management ICs before its acquisition by NXP Semiconductors in 2015.

The MC68HC11F1CPU4 belongs to the HC11 family - designed for deterministic real-time control in automotive, industrial, and appliance applications where code density, peripheral integration, and long-term availability were critical.

FAQ

What is the maximum operating frequency of the MC68HC11F1CPU4?

The MC68HC11F1CPU4 operates with a maximum E-clock frequency of 4 MHz, derived from an internal oscillator or external crystal connected to XTAL/EXTAL pins. This corresponds to a 2 MHz internal bus clock, defining instruction execution speed and peripheral timing resolution. The device does not support frequencies above 4 MHz E-clock per Freescale's electrical specifications and timing diagrams in the official datasheet.

Does the MC68HC11F1CPU4 include a hardware watchdog timer?

Yes, the MC68HC11F1CPU4 includes a Computer Operating Properly (COP) watchdog timer - a free-running counter that must be periodically cleared by software. If not serviced within the timeout window, it forces a system reset. This feature is implemented entirely in hardware and remains active in all operating modes except STOP, providing fail-safe operation for MC68HC11F1CPU4-based automotive and industrial controllers.

Can the MC68HC11F1CPU4 execute code from its on-chip EEPROM?

No, the MC68HC11F1CPU4 cannot execute code directly from EEPROM. Its memory map assigns EEPROM to the $E000–$E7FF address range for data storage only. Code execution occurs from ROM ($D000–$FFFF) or external memory in expanded mode. EEPROM is intended for nonvolatile parameter storage, calibration data, or firmware patches loaded into RAM at boot - not for XIP (execute-in-place) operation.

What serial communication interfaces are integrated into the MC68HC11F1CPU4?

The MC68HC11F1CPU4 integrates two independent serial interfaces: a Serial Communications Interface (SCI), which functions as a standard UART for asynchronous full-duplex communication, and a Serial Peripheral Interface (SPI) supporting master/slave operation with programmable clock polarity and phase. Both interfaces use memory-mapped registers and generate interrupts on transmit/receive completion, enabling robust host-peripheral and sensor-network communication in MC68HC11F1CPU4 designs.

Is the MC68HC11F1CPU4 pin-compatible with other HC11 family members?

No, the MC68HC11F1CPU4 is not pin-compatible with other HC11 variants such as the MC68HC11A8 or MC68HC11E9. It uses a 68-pin PLCC package with a unique pin assignment defined in Freescale's MC68HC11F1 Technical Data document (Figure 2-1). While functionally similar, differences in peripheral mapping, I/O port allocation, and power pin placement prevent direct PCB replacement without layout modification.