NXP Semiconductors MC68HC000CEI16R

Overview

MC68HC000CEI16R from Freescale Semiconductor (formerly Motorola) is a CMOS 16-bit microprocessor with 32-bit internal architecture, 24-bit address bus (16 MB addressing), 16-bit data bus, and 16 MHz maximum clock frequency. It implements the full M68000 instruction set, supports user/supervisor privilege modes, and features asynchronous bus control for flexible memory/peripheral interfacing in embedded control systems.

For engineers reviewing the MC68HC000CEI16R datasheet, MC68HC000CEI16R pinout, MC68HC000CEI16R application, or MC68HC000CEI16R equivalent, key selection criteria include bus timing compatibility (DTACK/BERR/HALT signaling), 64-pin DIP package footprint, 16 MHz operation under industrial temperature range (–40°C to +85°C), and legacy M68000 software binary compatibility.

Technical Context

The MC68HC000CEI16R executes instructions using a three-stage pipeline (fetch/decode/execute) and supports both synchronous and fully asynchronous bus cycles via DTACK handshake. Its status register includes supervisor/user mode bit, interrupt mask levels (I0–I2), and condition codes (N/Z/V/C/X), enabling real-time exception handling including bus error, address error, and seven autovectored interrupts.

It implements full M68000 programmer's model with eight 32-bit data/address registers, 16-bit external data path, and 24-bit external address path. The device uses static CMOS logic, permitting zero-power standby when halted, and requires external clock source with TTL-compatible input (CLK pin).

Key Specifications

Pinout & Package

MC68HC000CEI16R is housed in a 64-pin plastic Dual In-Line Package (Case 740-03, suffix L), with 0.3-inch body width and 0.1-inch pin pitch. Pin assignments conform to standard M68000 family layout for signal compatibility across MC68000/HC000/EC000 variants.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit microprocessor applications.

Compared with MC68HC000CEI16R, the MC68EC000RC16 offers smaller footprint but requires PCB redesign and loses DTACK timing flexibility, while the MC68000P16 matches pin count but increases thermal load and eliminates zero-power halt capability.

Availability

MC68HC000CEI16R is available at Aetrix Electronics and suitable for industrial PLC controller design, legacy CNC machine interface upgrades, and medical diagnostic equipment requiring stable component supply across extended production lifecycles.

Supply support for MC68HC000CEI16R 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) is a former Motorola division specializing in embedded processors, analog, and mixed-signal ICs for automotive, industrial, and networking markets.

The MC68HC000 belongs to the M68000 family - designed as a high-reliability, software-compatible evolution of the original MC68000, targeting long-lifecycle industrial and military applications with CMOS power efficiency and industrial temperature operation.

FAQ

What is the maximum operating frequency of the MC68HC000CEI16R?

The MC68HC000CEI16R is rated for a maximum clock frequency of 16 MHz across its full industrial temperature range (–40°C to +85°C). This specification is validated per Freescale's AC Electrical Characteristics table and applies to all timing-critical operations including instruction fetch, bus arbitration, and exception response. The MC68HC000CEI16R must be driven by a clean, TTL-compatible clock signal with defined rise/fall times to maintain timing margins.

Does the MC68HC000CEI16R support the full M68000 instruction set?

Yes, the MC68HC000CEI16R implements the complete M68000 instruction set, including all addressing modes, privilege-level instructions (e.g., MOVE from SR), and exception vectors. It maintains binary compatibility with the original MC68000, allowing direct execution of existing object code without recompilation. This is confirmed in Section 1.4 of the M68000 User's Manual and verified in Freescale's device characterization reports.

What package type and pin count does the MC68HC000CEI16R use?

The MC68HC000CEI16R uses a 64-pin plastic Dual In-Line Package (DIP) with 0.3-inch body width (Case 740-03, suffix L). This matches the pinout of the original MC68000P16 and MC68000P20, enabling direct socket replacement in legacy systems. Pin assignments are documented in Section 11.1 of the M68000 User's Manual and confirmed on Freescale's mechanical drawings.

How does the MC68HC000CEI16R handle bus timing with slow peripherals?

The MC68HC000CEI16R uses asynchronous bus control via the DTACK (Data Transfer Acknowledge) signal to interface with slow memory or peripherals. When DTACK is held low, the processor inserts wait states until the external device asserts DTACK high, eliminating need for fixed wait-state generators. This behavior is identical to the original MC68000 and is detailed in Sections 3.3 and 5.7 of the M68000 User's Manual.

Is the MC68HC000CEI16R suitable for new designs today?

The MC68HC000CEI16R remains viable for sustaining engineering, repair, and legacy system upgrades where M68000 architecture, 64-pin DIP footprint, and industrial temperature operation are mandatory. While not recommended for green-field designs due to performance and power limitations versus modern alternatives, it is actively stocked by Aetrix Electronics with guaranteed long-term availability and traceable sourcing for mission-critical maintenance programs.