NXP Semiconductors MC68HC000EI20

Overview

MC68HC000EI20 from Freescale Semiconductor (formerly Motorola) is a CMOS 16/32-bit microprocessor with 32-bit internal architecture, 24-bit address bus, and 16-bit data bus. It operates at 20 MHz maximum clock frequency, supports supervisor/user privilege modes, and executes the full M68000 instruction set including exception handling, bus arbitration, and asynchronous memory interfacing. It was widely used in industrial controllers and embedded systems requiring deterministic real-time response.

For engineers reviewing the MC68HC000EI20 datasheet, MC68HC000EI20 pinout, MC68HC000EI20 application, or MC68HC000EI20 equivalent, key selection considerations include its 68-pin PGA package, 20 MHz AC timing compliance, 5 V ±10% supply tolerance, asynchronous bus control via DTACK/BERR, and compatibility with legacy M6800 peripheral interfaces.

Technical Context

The MC68HC000EI20 implements the original M68000 architecture in high-reliability CMOS technology, retaining identical programmer's model, instruction set, and exception vector mapping as the NMOS MC68000. Its bus interface supports fully asynchronous operation with DTACK-driven wait-state insertion and BERR-triggered bus error recovery.

It features a 3-stage pipeline (fetch/decode/execute), 16 general-purpose 32-bit registers (8 data + 8 address), 256-byte on-chip instruction prefetch buffer, and hardware support for 7 interrupt levels plus non-maskable reset. The status register includes X, N, Z, V, C, T, S, and I bits for precise condition and mode control.

Key Specifications

Pinout & Package

MC68HC000EI20 is housed in a 68-lead Pin Grid Array (PGA) package (Case 767-02, P suffix), designed for through-hole mounting and high thermal reliability in convection-cooled industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC000EI20, the MC68EC000RC20 offers modern packaging but sacrifices M6800 peripheral compatibility, while the MC68000P12 provides pin-compatible legacy support at reduced speed and thermal capability-neither is drop-in replaceable without layout or firmware adaptation.

Availability

MC68HC000EI20 is available at Aetrix Electronics and suitable for industrial PLC controllers, avionics maintenance terminals, and ruggedized point-of-sale systems requiring stable component supply and long-term obsolescence management.

Supply support for MC68HC000EI20 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 MC68HC000EI20 belongs to the M68000 family, engineered for deterministic real-time control in industrial, test, and aerospace applications where binary compatibility, thermal robustness, and asynchronous bus flexibility were critical.

FAQ

What is the maximum operating frequency of the MC68HC000EI20?

The MC68HC000EI20 is rated for a maximum clock frequency of 20 MHz under specified conditions (5 V ±10%, –40°C to +85°C). This value is validated by Freescale's AC electrical specifications and corresponds to the fastest guaranteed instruction execution rate without timing violations in asynchronous bus cycles using DTACK handshaking.

Does the MC68HC000EI20 support the full M68000 instruction set?

Yes, the MC68HC000EI20 implements the complete M68000 instruction set architecture-including MOVE, ADD, SUB, AND, OR, bit manipulation, conditional branches, and exception-generating instructions like TRAP and ILLEGAL-with identical opcodes, addressing modes, and cycle counts as documented in the M68000 User's Manual. No instructions are omitted or altered.

What package type is used for the MC68HC000EI20?

The MC68HC000EI20 uses a 68-lead Pin Grid Array (PGA) package, specifically Case 767-02 (P suffix), with through-hole mounting and thermal characteristics suited for industrial convection cooling. This differs from QFP or DIP variants of other M68000 family members.

How does the MC68HC000EI20 handle bus errors?

When the MC68HC000EI20 detects an invalid memory access, it asserts the BERR signal and initiates a bus error exception, vectoring to address $000028. The processor saves the program counter, status register, and stack pointer onto the supervisor stack, enabling firmware to log the fault address and recover without system reset.

Is the MC68HC000EI20 pin-compatible with the original MC68000P12?

No, the MC68HC000EI20 is not pin-compatible with the MC68000P12. While both share the same 68-pin footprint, the MC68HC000EI20 uses a PGA package with different pin assignments (e.g., dedicated HALT, VMA, and FCx signals), whereas the MC68000P12 uses a 64-pin DIP with distinct signal mapping and no HALT pin.