NXP Semiconductors MC68HC000CRC16

Overview

MC68HC000CRC16 from Freescale Semiconductor (formerly Motorola) is a CMOS 16/32-bit microprocessor with 32-bit internal architecture, 16-bit external data bus, and 24-bit address bus supporting up to 16 MB memory space. It operates at 16 MHz maximum clock frequency, features two privilege modes (User/Supervisor), and implements full M68000 instruction set compatibility. It was widely used in industrial controllers and embedded systems requiring deterministic real-time execution.

For engineers reviewing the MC68HC000CRC16 datasheet, MC68HC000CRC16 pinout, MC68HC000CRC16 application, or MC68HC000CRC16 equivalent, key selection criteria include bus timing compliance (asynchronous/synchronous modes), exception vector handling, DTACK/BERR handshake support, and thermal performance in extended-temperature industrial environments.

Technical Context

The MC68HC000CRC16 implements the full M68000 instruction set with identical programmer's model, including 8 general-purpose 32-bit data/address registers, 16-bit status register with interrupt mask and mode bits, and hardware-supported exception vectoring. Its CMOS process enables lower power consumption versus the original NMOS MC68000 while maintaining pin- and code-compatibility.

It supports three bus operation modes: fully asynchronous, pseudo-asynchronous (with DTACK), and synchronous (with fixed clock-derived timing). Bus arbitration uses either 2-wire (BR/BG) or 3-wire (BR/BG/BS) protocols, and exception processing includes 256-byte vector table addressing with stack frame formats for bus error, address error, and interrupts.

Key Specifications

Pinout & Package

MC68HC000CRC16 is housed in a 68-lead Quad Flat Pack (QFP) package (Case 765A-05, RC suffix), measuring 24.2 mm × 24.2 mm with 0.65 mm lead pitch. Thermal pad on underside enhances heat dissipation in high-duty-cycle applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16/32-bit microprocessor applications.

Compared with MC68HC000CRC16, MC68EC000RC16 reduces pin count but sacrifices M6800 peripheral support, while MC68332ACPV16 offers higher integration and real-time peripherals at the cost of software incompatibility and increased complexity.

Availability

MC68HC000CRC16 is available at Aetrix Electronics and suitable for industrial PLC controllers, avionics maintenance terminals, and ruggedized test equipment requiring stable component supply and long-term lifecycle support.

Supply support for MC68HC000CRC16 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 fabless semiconductor company specializing in embedded processing, analog, and connectivity solutions for automotive, industrial, and networking markets.

The MC68HC000 belongs to the M68000 family, designed to deliver high-performance 32-bit computing in industrial and communications systems using mature, reliable CMOS technology with backward software compatibility.

FAQ

What is the maximum operating frequency of the MC68HC000CRC16?

The MC68HC000CRC16 is rated for a maximum clock frequency of 16 MHz under specified conditions (V_CC = 5.0 V ±5%, T_A = –40°C to +85°C). This frequency determines the upper bound of instruction execution speed and bus cycle timing; exceeding it may cause timing violations or undefined behavior. The MC68HC000CRC16 achieves this rating using CMOS process enhancements over the original NMOS MC68000.

Does the MC68HC000CRC16 support the full M68000 instruction set?

Yes, the MC68HC000CRC16 implements the complete M68000 instruction set, including all addressing modes, arithmetic/logic operations, and exception-handling instructions. Software compiled for the original MC68000 executes identically on the MC68HC000CRC16 without modification, preserving binary compatibility across generations of M68k-based systems.

What package type is used for the MC68HC000CRC16?

The MC68HC000CRC16 is packaged in a 68-lead Quad Flat Pack (QFP) with case number 765A-05 (RC suffix), measuring 24.2 mm × 24.2 mm and featuring 0.65 mm lead pitch. This surface-mount package includes an exposed thermal pad on the underside to improve heat dissipation in thermally constrained industrial applications.

How does the MC68HC000CRC16 handle bus errors?

When the MC68HC000CRC16 detects an invalid memory or I/O access (e.g., unmapped address or non-responsive peripheral), it asserts the BERR signal and initiates a bus error exception. This triggers a vector fetch from address $000028, pushes the program counter and status register onto the supervisor stack, and transfers control to the registered handler-enabling robust fault recovery in embedded systems.

Is the MC68HC000CRC16 pin-compatible with the original MC68000?

No, the MC68HC000CRC16 is not pin-compatible with the original NMOS MC68000 due to differences in package (68-lead QFP vs. 64-lead DIP or PGA) and signal assignments (e.g., added V_SS and V_DD pins for CMOS power integrity). However, it is functionally and electrically compatible with M68000 designs when adapted to its pinout and timing specifications.