NXP Semiconductors MC68HC000IEI16R

Overview

MC68HC000IEI16R from Freescale Semiconductor (formerly Motorola) is a CMOS 16-bit microprocessor compatible with the M68000 architecture, featuring a 24-bit address bus, 16-bit data bus, and 16 MHz maximum clock frequency. It operates at 5 V, supports supervisor/user privilege modes, and implements asynchronous bus control with DTACK, BERR, and HALT signals for embedded industrial control and legacy system upgrades.

For engineers reviewing the MC68HC000IEI16R datasheet, MC68HC000IEI16R pinout, MC68HC000IEI16R application, or MC68HC000IEI16R equivalent, key selection criteria include 16 MHz operation under industrial temperature range (–40°C to +85°C), 64-pin DIP package compatibility, asynchronous bus timing with programmable wait states, and full instruction set compatibility with MC68000-based firmware.

Technical Context

The MC68HC000IEI16R implements the original M68000 instruction set architecture in CMOS technology, retaining identical programmer's model, status register layout, and exception vector mapping. It supports both 8-bit and 16-bit bus operations via external control logic and uses asynchronous bus handshaking with DTACK for variable memory access timing.

Its internal architecture includes seven 32-bit data/address registers, a 16-bit ALU, and dedicated bus arbitration logic supporting 2-wire and 3-wire protocols. The processor executes instructions in microcoded form with cycle-accurate timing matching the original NMOS MC68000 at equivalent clock rates.

Key Specifications

Pinout & Package

MC68HC000IEI16R is housed in a 64-pin plastic dual in-line package (Case 740-03, L suffix), with 0.3-inch body width and 0.1-inch pin pitch. Pin functions follow the standard MC68000 pinout with CMOS-compatible voltage thresholds and drive strengths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68EC000RC16 and MC68000P16, the MC68HC000IEI16R uniquely balances 5 V bus compatibility, industrial temperature operation, and direct NMOS MC68000 firmware equivalence-making it the sole viable option for maintaining legacy systems without hardware or software modification.

Availability

MC68HC000IEI16R is available at Aetrix Electronics and suitable for industrial PLC controllers, legacy test equipment, avionics maintenance terminals, and railway signaling interfaces requiring stable component supply over extended product lifecycles.

Supply support for MC68HC000IEI16R 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) was a leading designer of embedded processors and analog/mixed-signal ICs, founded as Motorola's semiconductor division.

The MC68HC000IEI16R belongs to the M68000 family of general-purpose microprocessors designed for industrial control, instrumentation, and legacy system modernization where binary compatibility and long-term availability are essential.

FAQ

What is the maximum operating frequency of the MC68HC000IEI16R?

The MC68HC000IEI16R is rated for a maximum clock frequency of 16 MHz under industrial temperature conditions (–40°C to +85°C). This specification is validated per Freescale's AC electrical characteristics tables and reflects guaranteed timing margins for all instruction cycles and bus operations. The MC68HC000IEI16R maintains full instruction set compatibility at this speed, matching the performance envelope of the original NMOS MC68000-16.

Does the MC68HC000IEI16R support the same instruction set as the original MC68000?

Yes, the MC68HC000IEI16R implements the complete M68000 instruction set architecture with identical opcode encoding, addressing modes, and exception behavior. All documented instructions-including MOVE, ADD, SUB, BSR, JSR, and exception-generating opcodes-execute with cycle-accurate timing matching the NMOS version. The MC68HC000IEI16R is binary-compatible and requires no firmware changes when replacing MC68000P12/P16 parts.

What package type is used for the MC68HC000IEI16R?

The MC68HC000IEI16R is supplied in a 64-pin plastic dual in-line package (DIP) conforming to Case 740-03 mechanical dimensions, with 0.3-inch body width and 0.1-inch pin pitch. This package enables direct socket replacement in legacy boards originally designed for the MC68000P16, preserving PCB layout and assembly processes without redesign.

How does the MC68HC000IEI16R handle bus errors and exceptions?

The MC68HC000IEI16R uses a fixed 256-byte exception vector table starting at address $000000, with dedicated vectors for reset, bus error, address error, interrupts, and traps. Upon assertion of BERR or an invalid address, the processor pushes program counter and status register onto the supervisor stack and jumps to the corresponding vector. The MC68HC000IEI16R fully supports all documented exception types defined in the M68000 User's Manual.

Is the MC68HC000IEI16R compatible with M6800-series peripheral ICs?

Yes, the MC68HC000IEI16R includes explicit M6800 peripheral interface support as documented in Section 10.11 of the M68000 User's Manual. It provides compatible timing waveforms, control signal polarity, and handshake protocols for devices such as the MC6821 PIA and MC6850 ACIA. This capability is retained from the original MC68000 design and verified in the MC68HC000IEI16R's AC electrical specifications.