NXP Semiconductors MC908QY1ACDWE

Overview

MC908QY1ACDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB Flash, 192 B RAM, 10-bit ADC, on-chip oscillator, COP watchdog, and keyboard interrupt module - designed for low-cost, low-power embedded control in appliance panels, industrial sensors, and battery-powered instrumentation.

For engineers reviewing the MC908QY1ACDWE datasheet, MC908QY1ACDWE pinout, MC908QY1ACDWE application, or MC908QY1ACDWE equivalent, this page delivers verified technical context, package mapping, security byte configuration guidance, and real-world use cases aligned to the QYxA family's documented memory map, AWU timing, and LVI trip thresholds.

Technical Context

The MC908QY1ACDWE implements the HCS08 CPU core with 4 KB of on-chip SuperFlash® memory, supporting in-system programming and 100,000 write/erase cycles. It integrates a 10-bit ADC with 8 input channels, auto-wakeup timer with programmable sleep intervals, and dual-clock architecture (RC + XTAL) enabling seamless internal-to-external clock switching.

Security enforcement occurs during monitor mode entry: host must supply eight user-defined bytes matching locations $FFF6–$FFFD; entry is denied if five or more are zero. The device supports WAIT and STOP low-power modes, with LVI reset threshold configurable at 2.5 V or 3.7 V via CONFIG register bits.

Key Specifications

Pinout & Package

MC908QY1ACDWE is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package, 300 mil body width, 0.65 mm lead pitch, RoHS-compliant, with thermal pad not present. Pin numbering follows standard JEDEC MS-013AC orientation (pin 1 marked by notch or dot).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QY2ACDWE, the MC908QY1ACDWE trades Flash capacity for lower unit cost in fixed-function designs; versus MC908QT1ACDWE, it provides dedicated KBI hardware that reduces CPU load by 70% during keypad polling - critical for battery lifetime in intermittent-use devices.

Availability

MC908QY1ACDWE is available at Aetrix Electronics and suitable for appliance control panels, industrial sensor nodes, smart thermostat interfaces, and portable medical monitors requiring stable component supply across extended production lifecycles.

Supply support for MC908QY1ACDWE 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 MCU architectures for cost-sensitive, low-power embedded systems with robust industrial qualification.

The MC68HC908QYxA family was engineered for appliance and instrumentation applications demanding integrated analog peripherals, secure firmware update paths, and sub-10 µA STOP-mode current - all in compact SOIC packaging.

FAQ

What is the maximum operating frequency of the MC908QY1ACDWE?

The MC908QY1ACDWE supports a maximum bus clock frequency of 20 MHz, derived from its internal RC oscillator (trimmable up to 8 MHz) or external crystal (up to 8 MHz), with optional BUSCLKX4 output for timing-critical debug operations. Its HCS08 core executes instructions at two bus clocks per cycle, achieving up to 10 million instructions per second (MIPS) at full speed.

How does the security feature work on the MC908QY1ACDWE?

The MC908QY1ACDWE enforces security during monitor mode entry: the host must transmit eight bytes matching those stored at Flash addresses $FFF6–$FFFD. If five or more of those bytes are $00, monitor mode entry is denied. Users must program these locations - even with dummy values - to prevent unauthorized access, as blank locations default to $00.

Can the MC908QY1ACDWE operate from a single 3 V battery?

Yes, the MC908QY1ACDWE operates across 2.7–5.5 V, making it compatible with single 3 V lithium or alkaline cells. Its LVI module can be configured for 2.5 V reset threshold, ensuring safe shutdown before battery depletion. In STOP mode, typical current draw is 1.5 µA at 3 V and 25°C - enabling multi-year operation on CR2032 cells in low-duty-cycle applications.

What peripherals are included in the MC908QY1ACDWE?

The MC908QY1ACDWE integrates a 10-bit ADC with 8 input channels, Auto Wakeup Module (AWU), Computer Operating Properly (COP) watchdog, Low-Voltage Inhibit (LVI), Keyboard Interrupt (KBI) for hardware key scanning, External Interrupt (IRQ), and dual-clock system (RC + XTAL). It lacks UART, SPI, or I²C - communication must be bit-banged or implemented via GPIO.

Is there a drop-in replacement for the MC908QY1ACDWE with more Flash memory?

The MC908QY2ACDWE is a pin-compatible and register-compatible upgrade offering 8 KB Flash in the same 20-pin SOIC package. Firmware compiled for MC908QY1ACDWE runs unchanged on MC908QY2ACDWE, and all peripheral initialization sequences remain identical - enabling seamless capacity scaling without PCB or driver changes.