NXP Semiconductors MC68EC000EI20

Overview

MC68EC000EI20 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 where deterministic real-time execution and ROM-based boot are required.

For engineers reviewing the MC68EC000EI20 datasheet, MC68EC000EI20 pinout, MC68EC000EI20 application, or MC68EC000EI20 equivalent, key selection criteria include its 24-bit address capability, lack of memory management unit, compatibility with M68000-family development tools, and suitability for systems requiring external bus arbitration and synchronous/asynchronous peripheral interfacing.

Technical Context

The MC68EC000EI20 implements the full M68000 integer instruction set-including data movement, arithmetic, logical, bit manipulation, and program control instructions-with identical addressing modes (register direct, absolute short/long, PC-relative, indexed, etc.) as the MC68000. Its execution unit uses a three-stage pipeline (fetch-decode-execute) and supports both big-endian byte ordering and asynchronous bus timing with programmable wait-state insertion.

Unlike the MC68000, the MC68EC000EI20 omits the vector base register (VBR), transparent translation registers, and coprocessor interface signals-reflecting its embedded focus and simplified supervisor model. It retains full exception handling (reset, bus error, address error, trap vectors) but excludes virtual memory support and MMU-related instructions.

Key Specifications

Pinout & Package

MC68EC000EI20 is housed in a 64-pin ceramic quad flat pack (CQFP) package with 0.6 mm lead pitch, designed for high-reliability industrial and aerospace applications requiring hermetic sealing and thermal stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68EC000FN20 and MC68HC000P12, the MC68EC000EI20 delivers higher clock speed and superior thermal/mechanical robustness in a hermetically sealed package-making it the preferred choice for mission-critical industrial and aerospace deployments where long-term reliability outweighs cost or power savings.

Availability

MC68EC000EI20 is available at Aetrix Electronics and suitable for industrial PLC controllers, point-of-sale terminals, legacy test equipment, and avionics maintenance units requiring stable component supply across extended product lifecycles.

Supply support for MC68EC000EI20 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 pioneering designer of microprocessors and embedded controllers, known for the M68000 family's architectural clarity and long-term industry adoption.

The MC68EC000EI20 belongs to Motorola's embedded controller product line, developed to deliver M68000 software compatibility in cost-optimized, high-reliability packages for industrial and military applications without memory management overhead.

FAQ

What is the maximum operating frequency of the MC68EC000EI20?

The MC68EC000EI20 is rated for a maximum clock frequency of 20 MHz under specified voltage and temperature conditions. This frequency defines the upper bound for instruction execution rate and bus cycle timing; exceeding it may cause timing violations or undefined behavior. The MC68EC000EI20 does not support dynamic frequency scaling or PLL-based clock multiplication.

Does the MC68EC000EI20 include an on-chip memory management unit (MMU)?

No, the MC68EC000EI20 does not include an on-chip MMU. It lacks the vector base register (VBR), transparent translation registers, and associated MMU instructions found in the MC68010 and later full-featured processors. The MC68EC000EI20 relies entirely on external logic for memory mapping and protection, aligning with its embedded controller role.

Is the MC68EC000EI20 pin-compatible with the standard MC68000?

No, the MC68EC000EI20 is not pin-compatible with the MC68000. While functionally compatible at the instruction set level, the MC68EC000EI20 uses a 64-pin CQFP package with different pin assignments-including omission of coprocessor interface signals and MMU-related pins-requiring PCB redesign for migration from the 64-pin DIP MC68000.

What type of reset vector does the MC68EC000EI20 use?

Upon assertion of the RESET signal, the MC68EC000EI20 initializes its program counter to the fixed address $000000 and begins fetching instructions from that location. This hardwired reset vector eliminates dependency on external configuration pins or boot ROM selection logic, enabling direct execution from EPROM or flash memory mapped at the lowest address range.

Can the MC68EC000EI20 interface directly with 32-bit peripherals?

The MC68EC000EI20 features a 16-bit external data bus, so interfacing with 32-bit peripherals requires two consecutive bus cycles per 32-bit transfer. External glue logic or a bus-width adapter is needed to manage byte enables and address sequencing; the MC68EC000EI20 itself does not provide native 32-bit data burst capability or split-transaction support.