NXP Semiconductors MC68EC000EI20R

Overview

MC68EC000EI20R from Motorola is a 16-/32-bit embedded controller CPU implementing the M68000 instruction set architecture, featuring a 20 MHz maximum clock frequency, 32-bit internal data path, 24-bit address bus (16 MB addressable space), and no on-chip MMU or FPU. It targets cost-sensitive industrial control, point-of-sale terminals, and legacy instrumentation systems requiring ROM-based boot and minimal peripheral integration.

For engineers reviewing the MC68EC000EI20R datasheet, MC68EC000EI20R pinout, MC68EC000EI20R application, or MC68EC000EI20R equivalent, key selection criteria include its EC-series embedded feature set (no MMU/FPU, simplified bus timing), 20 MHz operation at 5 V, compatibility with M68000 software, and suitability for non-virtual-memory real-time control firmware.

Technical Context

The MC68EC000EI20R implements the full M68000 integer instruction set with identical addressing modes and register model (eight 32-bit data and address registers, 32-bit program counter, 16-bit status register), but omits the MMU and FPU support present in full M68000 variants. Its bus interface uses asynchronous, non-multiplexed 24-bit address and 16-bit data lines with discrete /AS, /DS, /UDS, /LDS, and /RW control signals.

It operates exclusively in 5 V logic, supports single-step debugging via BKPT instruction and trace mode, and executes instructions in 2–12 clock cycles depending on addressing mode and operand size - e.g., MOVE.L (A0)+,(A1)+ requires 12 cycles, while ADD.W D0,D1 takes 4 cycles.

Key Specifications

Pinout & Package

MC68EC000EI20R is housed in a 68-pin Plastic Leaded Chip Carrier (PLCC) package with J-type leads. Pin numbering follows standard PLCC convention (Pin 1 marked by corner notch, counterclockwise).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68EC000FN20, the MC68EC000EI20R offers easier prototyping and field serviceability via PLCC socket; compared with MC68HC000P12, it delivers 67% higher throughput for time-critical control loops at the cost of higher static power dissipation.

Availability

MC68EC000EI20R is available at Aetrix Electronics and suitable for industrial PLC controllers, point-of-sale terminals, legacy test equipment, and medical diagnostic modules requiring stable component supply over extended production lifecycles.

Supply support for MC68EC000EI20R 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) was a pioneer in 32-bit microprocessor architecture, known for robust industrial-grade ICs and comprehensive developer documentation.

The MC68EC000EI20R belongs to Motorola's EC (Embedded Controller) product line, designed specifically for cost-optimized, non-virtual-memory embedded systems where software compatibility with the M68000 ecosystem outweighs the need for advanced memory management or floating-point acceleration.

FAQ

What is the maximum operating frequency of the MC68EC000EI20R?

The MC68EC000EI20R is rated for a maximum clock frequency of 20 MHz under specified 5 V ±5% supply and commercial temperature conditions. This frequency determines worst-case instruction execution timing - for example, a 32-bit memory-to-memory move requires 12 cycles, or 600 ns at 20 MHz. Exceeding this limit risks setup/hold violations and undefined behavior.

Does the MC68EC000EI20R include an on-chip memory management unit (MMU)?

No, the MC68EC000EI20R does not include an MMU. It is explicitly designed as an embedded controller variant of the M68000 family, omitting both the MMU and FPU to reduce cost, power, and die area. Memory management must be implemented externally using discrete logic or a companion chip like the MC68851 if required.

What package type is used for the MC68EC000EI20R?

The MC68EC000EI20R uses a 68-pin Plastic Leaded Chip Carrier (PLCC) package with J-shaped leads. This package supports socket-based prototyping and field-replaceable designs, and is compatible with standard PLCC footprint land patterns and reflow soldering profiles for leaded components.

Is the MC68EC000EI20R software-compatible with the original MC68000?

Yes, the MC68EC000EI20R implements the complete M68000 integer instruction set and register model, including all addressing modes and condition codes. Binaries compiled for the MC68000 will execute identically on the MC68EC000EI20R, provided they do not rely on MMU or FPU instructions absent from the EC variant.

What voltage supply does the MC68EC000EI20R require?

The MC68EC000EI20R requires a single 5.0 V ±5% DC supply. It is not 3.3 V tolerant and lacks internal voltage regulation - external filtering and decoupling (e.g., 0.1 µF ceramic per V_CC/GND pair) are mandatory to meet AC noise specifications and ensure reliable reset and bus timing.