NXP Semiconductors MC68EC000EI8R2

Overview

MC68EC000EI8R2 from Motorola is a 16-/32-bit embedded controller CPU implementing the M68000 instruction set architecture, featuring a 24-bit address bus (16 MB address space), 16-bit data bus, no on-chip MMU or FPU, and operation at up to 8 MHz in CMOS technology for low-power industrial control applications.

For engineers reviewing the MC68EC000EI8R2 datasheet, MC68EC000EI8R2 pinout, MC68EC000EI8R2 application, or MC68EC000EI8R2 equivalent, key selection criteria include its embedded-optimized silicon (no MMU/FPU), 8 MHz max clock, 24-bit addressing, single 5 V supply requirement, and compatibility with legacy M68000 software while targeting cost-sensitive, non-virtual-memory systems.

Technical Context

The MC68EC000EI8R2 implements the full M68000 integer instruction set-including data movement, arithmetic, logical, bit manipulation, and program control instructions-with identical addressing modes (register direct, memory indirect, PC-relative, absolute) and condition code behavior as the MC68000. It lacks coprocessor interface support and does not execute MC68881/882 floating-point or MC68851 MMU instructions.

It uses a three-stage pipeline (fetch, decode, execute), supports asynchronous bus timing with separate AS, DTACK, and R/W signals, and requires external latching for address/data multiplexing. Its supervisor/user mode distinction enables basic privilege separation but omits virtual memory management or protected-mode features found in later family members like the MC68020.

Key Specifications

Pinout & Package

MC68EC000EI8R2 is housed in an 84-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead configuration, designed for socketed or surface-mount PCB assembly. Pin numbering follows standard PLCC convention (Pin 1 marked by notch/dot, counterclockwise).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68EC000EI8R2, the MC68EC000FN8R2 offers identical performance in a surface-mount-friendly PQFP, while the MC68SEC000P8 provides long-term sourcing continuity through Freescale's post-2004 product stewardship-both preserve binary compatibility and eliminate firmware porting effort.

Availability

MC68EC000EI8R2 is available at Aetrix Electronics and suitable for industrial motor control, legacy HMI upgrades, medical diagnostic equipment, and avionics subsystems requiring stable component supply across multi-year production cycles.

Supply support for MC68EC000EI8R2 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

Motorola Semiconductor (now part of NXP Semiconductors via Freescale acquisition) pioneered the M68000 family, establishing foundational CISC architecture for embedded and desktop computing in the 1980s.

The MC68EC000 series was designed specifically for cost-sensitive, non-virtual-memory embedded systems-delivering M68000 software compatibility with reduced silicon area, lower power, and industrial-grade reliability.

FAQ

What is the maximum operating frequency of the MC68EC000EI8R2?

The MC68EC000EI8R2 is rated for a maximum clock frequency of 8 MHz. This specification is guaranteed across the full industrial temperature range (–40°C to +85°C) and supply voltage (4.75 V to 5.25 V). Exceeding 8 MHz may result in undefined instruction execution or bus timing violations, as the internal pipeline and bus interface are characterized only up to this speed. The MC68EC000EI8R2 does not support dynamic frequency scaling or overclocking.

Does the MC68EC000EI8R2 include an integrated MMU or FPU?

No, the MC68EC000EI8R2 contains neither a Memory Management Unit nor a Floating-Point Unit. It is a streamlined implementation of the M68000 core optimized for embedded use-omitting these blocks reduces die size, power consumption, and cost. Software requiring virtual memory or IEEE 754 floating-point operations must rely on external MMU (e.g., MC68851) or FPU (e.g., MC68881) chips, though the MC68EC000EI8R2 lacks the coprocessor handshake signals needed to interface with them.

What package type is used for the MC68EC000EI8R2?

The MC68EC000EI8R2 is packaged in an 84-pin Plastic Leaded Chip Carrier (PLCC) with J-leads. This package supports both socketed prototyping and surface-mount reflow assembly. Pin 1 is identified by a notch or dot in the upper-left corner when viewed from the top, and pin numbering proceeds counterclockwise. Thermal performance is adequate for typical embedded power dissipation (<300 mW), with no integrated heat slug.

Is the MC68EC000EI8R2 software-compatible with the original MC68000?

Yes, the MC68EC000EI8R2 executes the complete M68000 integer instruction set with identical opcodes, addressing modes, register behavior, and exception vectors. All user-mode and supervisor-mode integer instructions-including MOVE, ADD, Bcc, JSR, and TRAP-behave identically. Firmware compiled for the MC68000 runs unchanged on the MC68EC000EI8R2, provided it does not depend on absent hardware features like the MC68000's 24-bit address bus extension or external coprocessor interface.

What are the key differences between the MC68EC000EI8R2 and the MC68EC020?

The MC68EC000EI8R2 is a 16-/32-bit CPU with a 24-bit address bus, 16-bit data bus, and no MMU/FPU, while the MC68EC020 is a full 32-bit CPU with 32-bit address and data buses, on-chip 256-byte instruction cache, and optional MMU support. The MC68EC020 executes instructions faster (up to 33 MHz), supports paged memory management, and adds new addressing modes and instructions (e.g., CAS, PFLUSH). The MC68EC000EI8R2 maintains strict M68000 binary compatibility; the MC68EC020 extends the architecture significantly.