NXP Semiconductors MC68HC908QY1MPE

Overview

MC68HC908QY1MPE from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 1 KB FLASH, 64 bytes RAM, internal RC oscillator (4 MHz typical), 8-pin SOIC package, and integrated ADC, KBI, and COP watchdog - designed for low-cost sensor interface and simple control in battery-powered industrial modules.

For engineers reviewing the MC68HC908QY1MPE datasheet, MC68HC908QY1MPE pinout, MC68HC908QY1MPE application, or MC68HC908QY1MPE equivalent, key selection criteria include its 8-pin SOIC footprint, 1 KB FLASH/64B RAM memory budget, internal oscillator trim capability, keyboard interrupt support for matrix input, and LVI reset threshold at 2.5 V nominal.

Technical Context

The MC68HC908QY1MPE implements the M68HC08 CPU core with 16-bit address bus, supporting WAIT/STOP low-power modes and a 4 MHz internal RC oscillator with factory-trimmed accuracy. Its System Integration Module (SIM) provides clock control, reset generation, and interrupt vectoring without external crystal dependency.

It integrates a 4-channel 8-bit ADC with software-triggered conversion, a 2-pin keyboard interrupt module (KBI) for wake-on-key events, and a Computer Operating Properly (COP) watchdog with selectable timeout via CONFIG1 register - all operating within a 2.7–5.5 V supply range.

Key Specifications

Pinout & Package

MC68HC908QY1MPE is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, compatible with standard surface-mount reflow processes and manual prototyping.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908QY2MPE and MC9RS08KA2CSC, the MC68HC908QY1MPE offers the smallest memory footprint and lowest cost in the QY family while retaining full KBI and LVI functionality - ideal for ultra-low-BOM sensor endpoints where code size is tightly constrained.

Availability

MC68HC908QY1MPE is available at Aetrix Electronics and suitable for industrial sensor nodes, smart thermostat interfaces, portable medical monitors, and LED lighting dimmers requiring stable component supply across long-lifecycle production programs.

Supply support for MC68HC908QY1MPE 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

NXP Semiconductors is a global semiconductor leader delivering secure, energy-efficient, and scalable solutions for automotive, industrial, IoT, and mobile applications.

The MC68HC908QY1MPE belongs to the legacy HCS08 microcontroller family, designed specifically for cost-sensitive, low-pin-count embedded control in battery-operated and space-constrained systems.

FAQ

What is the maximum operating frequency of the MC68HC908QY1MPE?

The MC68HC908QY1MPE operates at a maximum internal bus clock frequency of 4 MHz, derived from its factory-trimmed RC oscillator. This frequency is fixed and not user-adjustable via external components. The device does not support external crystal oscillators above 4 MHz, and its instruction execution rate is directly tied to this clock source. All timing-critical peripherals - including ADC conversion, COP timeout, and KBI sampling - are synchronized to this 4 MHz base.

Does the MC68HC908QY1MPE support in-circuit programming after soldering?

Yes, the MC68HC908QY1MPE supports in-circuit programming via its dedicated monitor mode using the PTA4/BUSCLKX4 pin as a serial programming interface. This requires applying a specific voltage sequence on reset and using compatible Freescale/NXP programming tools such as the DEMO9RS08KA2 evaluation board with appropriate firmware. No external programming header is needed, enabling field firmware updates and manufacturing flash programming without socketing.

Can the MC68HC908QY1MPE operate from a single 3.3 V supply?

Yes, the MC68HC908QY1MPE is fully specified to operate across a 2.7–5.5 V supply range, making it compatible with standard 3.3 V systems. At 3.3 V, the internal 4 MHz RC oscillator remains functional and stable, ADC performance meets datasheet specifications (INL ±2 LSB), and I/O pins are 5 V tolerant when configured as inputs - allowing direct interfacing with higher-voltage sensors or logic without level shifters.

How many analog input channels does the MC68HC908QY1MPE ADC support?

The MC68HC908QY1MPE integrates a single 8-bit successive-approximation ADC with four selectable input channels (AD0–AD3), mapped to PTA2, PTA3, PTA6, and PTA7 pins. Only one channel can be converted at a time, with conversion triggered by software or timer. Channel selection is controlled via the ADC Input Select Register (ADSCR), and the result is stored in the 8-bit ADC Data Register (ADR).

Is there hardware support for keyboard matrix scanning in the MC68HC908QY1MPE?

Yes, the MC68HC908QY1MPE includes a dedicated Keyboard Interrupt Module (KBI) with two input pins (KBI0 and KBI1) that support hardware-accelerated wake-on-key detection for 2×2 or 2×3 matrix keypads. The KBI detects transitions on either pin while the MCU is in STOP or WAIT mode and asserts an interrupt without CPU intervention - reducing average current consumption in keypad-based devices.