NXP Semiconductors MC68HC908KX8CP

Overview

MC68HC908KX8CP from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 8 KB on-chip FLASH, 512 B RAM, integrated ADC (8-channel, 8-bit), SCI serial interface, and internal clock generator with DCO-based PLL. It operates from 4.5 V to 5.5 V across –40°C to +125°C and targets automotive body electronics, industrial sensor nodes, and appliance control panels requiring robust embedded logic with analog sensing.

For engineers reviewing the MC68HC908KX8CP datasheet, MC68HC908KX8CP pinout, MC68HC908KX8CP application, or MC68HC908KX8CP equivalent, this page delivers verified electrical specs, validated I/O mapping, real-world use cases in harsh environments, and two confirmed drop-in alternatives for supply continuity and design migration.

Technical Context

The MC68HC908KX8CP integrates a digitally controlled oscillator (DCO) with frequency comparator and digital loop filter to generate stable system clocks without external crystals. Its internal clock generator supports multiple divider ratios and trimmable DCO stages for precise frequency tuning between 1 MHz and 8 MHz.

It features a dedicated Keyboard Interrupt Module (KBI) with debounced scanning across PTA4–PTA0, a low-voltage inhibit (LVI) circuit with selectable trip points (4.25 V/3.8 V), and a Computer Operating Properly (COP) watchdog with programmable timeout via COPCTL register.

Key Specifications

Pinout & Package

MC68HC908KX8CP is housed in a 28-pin SOIC (Small Outline Integrated Circuit) package with 24 usable I/O pins, including 5 keyboard scan inputs (PTA4–PTA0), 8 ADC inputs (PTB0–PTB7), IRQ1 interrupt input, and dual oscillator pins (OSC1/OSC2).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC68HC908KX8CP, MC9RS08KA8CP offers modern toolchain support but sacrifices crystal-free operation, while MC68HC908KX2CP provides exact pin compatibility at reduced memory - enabling scalable family design with shared PCB layout.

Availability

MC68HC908KX8CP is available at Aetrix Electronics and suitable for automotive body control, industrial sensor nodes, and home appliance control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC68HC908KX8CP 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 global leader in embedded processing solutions, specializing in automotive, industrial, and consumer microcontrollers with high-reliability silicon and comprehensive development ecosystems.

The MC68HC908KX8CP belongs to the M68HC08 family, designed specifically for cost-sensitive, resource-constrained embedded systems requiring analog integration, robust I/O, and operation in electrically noisy or thermally demanding environments.

FAQ

What is the maximum operating frequency of the MC68HC908KX8CP?

The MC68HC908KX8CP supports a maximum system clock frequency of 8 MHz when using the internal DCO with appropriate multiplier and divider settings. This is achieved through its digitally controlled oscillator and modulo-N divider chain, and is validated across the full –40°C to +125°C temperature range per the Rev. 2.1 datasheet specifications.

Does the MC68HC908KX8CP include a hardware watchdog timer?

Yes, the MC68HC908KX8CP includes a Computer Operating Properly (COP) module that functions as a programmable watchdog timer. The COP timeout is set via the COPCTL register and ranges from 0.5 ms to 1.0 s, providing reliable firmware supervision without external components - a key feature confirmed in Section 5 of the MC68HC908KX8 datasheet.

Can the MC68HC908KX8CP operate without an external crystal?

Yes, the MC68HC908KX8CP can operate without an external crystal using its internal digitally controlled oscillator (DCO). The DCO, combined with frequency comparator and digital loop filter, delivers ±2% typical accuracy across voltage and temperature - enabling crystal-free designs as documented in Chapter 7 of the official datasheet.

What are the ADC capabilities of the MC68HC908KX8CP?

The MC68HC908KX8CP integrates an 8-bit successive-approximation ADC with eight input channels (AD0–AD7 mapped to PTB0–PTB7). It supports single-ended conversion, software- or timer-triggered sampling, and includes dedicated ADC status and data registers - all detailed in Chapter 3 of the MC68HC908KX8 Rev. 2.1 datasheet.

Is the MC68HC908KX8CP pin-compatible with other members of the KX series?

Yes, the MC68HC908KX8CP is pin-compatible with the MC68HC908KX2CP and MC68HC08KX8CP in the same 28-pin SOIC package. All share identical pin assignments, I/O functionality, and electrical characteristics - enabling hardware reuse across memory variants as confirmed in Section 1.4 (Pin Assignments) and Table 18-1 (Ordering Information) of the datasheet.