NXP Semiconductors MC68HC16Z1CEH20

Overview

MC68HC16Z1CEH20 from Freescale Semiconductor is a 16-bit microcontroller unit (MCU) featuring the CPU16 core, 20 MHz maximum bus frequency, 512-byte on-chip SRAM, 32 KB masked ROM (Z2/Z3 variants), and integrated peripherals including ADC, QSM, and GPT. It targets embedded control in industrial instrumentation and automotive body electronics where deterministic real-time response and low-power STOP mode operation are required.

For engineers reviewing the MC68HC16Z1CEH20 datasheet, MC68HC16Z1CEH20 pinout, MC68HC16Z1CEH20 application, or MC68HC16Z1CEH20 equivalent, key selection criteria include CPU16 instruction set compatibility with HC11 legacy code, external bus interface timing at 20 MHz, SIM-based interrupt arbitration, and SRAM retention during STOP mode - all critical for migration paths and power-constrained designs.

Technical Context

The MC68HC16Z1CEH20 implements the CPU16 core with 16-bit data path, 24-bit address space, and support for indexed, extended, and relative addressing modes. Its System Integration Module (SIM) provides clock synthesis, reset control, interrupt arbitration, and chip-select logic for external memory mapping.

It integrates a 10-bit analog-to-digital converter with 8 input channels, a Queued Serial Module (QSM) supporting both SPI-like QSPI and UART-like SCI protocols, and a General-Purpose Timer with input capture/output compare capability - all accessible via memory-mapped registers and synchronized to the internal bus clock.

Key Specifications

Pinout & Package

MC68HC16Z1CEH20 is housed in a 112-pin Plastic Quad Flat Pack (PQFP) package with 0.65 mm lead pitch, compliant with JEDEC MS-026. Pin assignments follow the M68HC16Z series standard layout defined in Section 3.4 of the User's Manual.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC16Z1CEH20, MC68HC16Z2CFN20 offers identical timing, packaging, and peripheral behavior but adds mask ROM for reduced BOM cost and faster boot; MC9328MX1CZK provides vastly higher compute throughput but abandons HC16 toolchain and instruction compatibility entirely.

Availability

MC68HC16Z1CEH20 is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, medical infusion pumps, and energy meter data loggers requiring stable component supply across long-lifecycle programs.

Supply support for MC68HC16Z1CEH20 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, analog, and mixed-signal ICs for automotive, industrial, and networking markets.

The M68HC16Z series was developed as a high-reliability, low-power 16-bit MCU family targeting legacy HC11 migration paths and deterministic real-time control in harsh environments - emphasizing code compatibility, robust reset/interrupt handling, and external bus flexibility.

FAQ

What is the maximum operating frequency of the MC68HC16Z1CEH20?

The MC68HC16Z1CEH20 supports a maximum bus frequency of 20 MHz, derived from its internal clock synthesizer and external crystal input (CLKIN). This frequency governs external memory access timing, peripheral bus cycles, and instruction execution throughput. The CPU16 core executes most instructions in 2–6 bus cycles, yielding effective throughput up to 10 MIPS under typical conditions. All timing specifications assume operation within the rated temperature and voltage ranges specified in the Freescale M68HC16Z Series User's Manual.

Does the MC68HC16Z1CEH20 include on-chip flash or ROM memory?

No, the MC68HC16Z1CEH20 does not integrate mask-programmed ROM or flash memory. Unlike the MC68HC16Z2/Z3 variants which include 32 KB of on-chip masked ROM, the Z1 variant relies on external memory for program storage - typically EPROM or Flash connected via its multiplexed AD0–AD15 and dedicated A16–A23 address bus. Its on-chip memory consists solely of 512 bytes of SRAM for data and stack operations.

How does the MC68HC16Z1CEH20 handle power management in low-power applications?

The MC68HC16Z1CEH20 supports three low-power states: Freeze, LPSTOP, and STOP. In STOP mode, the CPU, SIM, and most peripherals are halted while SRAM and register contents are retained, drawing less than 10 µA at 5 V. Wake-up occurs via RESET, interrupt, or external pin edge. The SIM's software watchdog and periodic interrupt timer provide autonomous wake-up triggers, making MC68HC16Z1CEH20 suitable for battery-powered nodes requiring infrequent sensor polling and long standby durations.

Can the MC68HC16Z1CEH20 be debugged without JTAG hardware?

Yes, the MC68HC16Z1CEH20 supports Background Debug Mode (BDM) using a single-wire serial interface (BKGD pin), eliminating the need for dedicated JTAG circuitry. BDM allows full read/write access to CPU registers, memory, and peripheral control registers during runtime or halted states. It supports breakpoint insertion, step-through execution, and flash programming - all through the BKGD pin and associated pull-up resistor, significantly reducing debug footprint and board complexity compared to multi-pin JTAG solutions.

What serial communication protocols are supported by the MC68HC16Z1CEH20?

The MC68HC16Z1CEH20 integrates a Queued Serial Module (QSM) that implements two distinct protocols: Queued Serial Peripheral Interface (QSPI), compatible with Motorola SPI timing and framing, and Serial Communication Interface (SCI), functionally equivalent to an industry-standard UART. Both operate independently, share no registers, and support full-duplex operation. QSPI supports master/slave modes with programmable clock polarity and phase; SCI supports 8-N-1, 9-bit, and LIN-compatible formats with automatic break detection - enabling direct connection to sensors, displays, and automotive networks without external level shifters or protocol translators.