NXP Semiconductors MC908QY2ACDWE

Overview

MC908QY2ACDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 2 KB FLASH, 128 B RAM, 10-bit ADC, on-chip oscillator, COP watchdog, and AWU wake-up module. It operates at up to 8 MHz bus frequency, supports 2.7–5.5 V supply, and targets low-cost embedded control in industrial sensors and appliance subsystems.

For engineers reviewing the MC908QY2ACDWE datasheet, MC908QY2ACDWE pinout, MC908QY2ACDWE application, or MC908QY2ACDWE equivalent, key selection criteria include FLASH security byte validation ($FFF6–$FFFD), internal oscillator trim register (ICSTRM) configuration, AWU interrupt latency, and LVI reset threshold selection.

Technical Context

The MC908QY2ACDWE implements the HCS08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing modes. Its memory map includes 2 KB of on-chip FLASH with block protection and EEPROM emulation capability, plus 128 bytes of RAM with direct-page access optimization.

Peripherals include a 10-bit successive-approximation ADC with 8 input channels, Auto Wakeup Module with programmable timeout (1–1024 ms), Low-Voltage Inhibit with selectable trip points (2.5 V or 3.8 V), and Keyboard Interrupt Module supporting up to 8 inputs with polarity control.

Key Specifications

Pinout & Package

MC908QY2ACDWE is housed in a 28-pin SOIC package (SOIC-28W) with 0.300-inch body width and standard JEDEC MS-013AC footprint. Pin assignments follow the QYxA family layout with dedicated I/O, analog, power, and oscillator pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QY2ACDWE, the QY4 variant offers headroom for complex control algorithms and secure firmware updates, while the QT2 variant reduces BOM cost by removing unused analog circuitry - enabling optimized trade-offs between sensing capability, memory, and unit cost.

Availability

MC908QY2ACDWE is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance controllers, and portable medical devices requiring stable component supply, long-lifecycle support, and consistent parametric performance across temperature ranges.

Supply support for MC908QY2ACDWE 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) pioneered 8-bit microcontroller architectures for cost-sensitive, high-volume embedded applications with robust industrial qualification.

The MC68HC908QYxA family was designed for ultra-low-cost, low-power control in appliances, sensors, and consumer electronics - emphasizing integrated peripherals, flash security, and simplified development toolchain compatibility.

FAQ

What is the FLASH memory size and endurance specification for MC908QY2ACDWE?

The MC908QY2ACDWE integrates 2 KB of on-chip FLASH memory rated for 10,000 erase/write cycles per block. Endurance is maintained through proper use of page/mass erase commands and adherence to voltage and timing specifications during programming. The MC908QY2ACDWE datasheet specifies that EEPROM emulation libraries extend effective data retention to 100,000 cycles using wear-leveling techniques across multiple FLASH pages.

Does MC908QY2ACDWE support crystal oscillator operation?

Yes, MC908QY2ACDWE supports external crystal oscillator operation via XTAL/EXTAL pins. It accepts fundamental-mode crystals from 32.768 kHz to 8 MHz. The oscillator circuit includes internal load capacitors and supports both series and parallel resonant configurations. Crystal startup time is typically 1–2 ms, and the MC908QY2ACDWE automatically switches to crystal clock after stabilization when configured in OSCCTL register.

How does the security feature work in MC908QY2ACDWE monitor mode?

The MC908QY2ACDWE security feature requires host tools to send eight matching bytes to locations $FFF6–$FFFD during monitor mode entry. If five or more of those bytes are $00, monitor mode is denied - preventing accidental or malicious bypass. This mechanism applies exclusively to the MC908QY2ACDWE and other QYxA family members; security behavior is enforced in hardware and cannot be disabled.

What is the ADC resolution and input channel count on MC908QY2ACDWE?

The MC908QY2ACDWE features a 10-bit successive-approximation ADC with eight single-ended input channels (AD0–AD7), mapped to PORTA and PORTB pins. Conversion results are stored in 16-bit ADRL/ADRH registers. Input voltage range is 0–VREFH, with VREFH configurable to VDD or external reference. Minimum conversion time is 12 bus cycles at 8 MHz bus clock.

Can MC908QY2ACDWE operate from a single 3.3 V supply?

Yes, MC908QY2ACDWE operates across 2.7–5.5 V, making it fully compatible with 3.3 V systems. At 3.3 V, maximum bus frequency is 6.25 MHz (per electrical specs), and all I/O pins are 5 V tolerant when configured as inputs. Internal LVI can be set to 2.5 V trip point to ensure safe operation down to battery discharge levels common in 3.3 V designs.