NXP Semiconductors MC908QY1ACDTE

Overview

MC908QY1ACDTE from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 4 KB FLASH, 192 B RAM, 10-bit ADC (8-channel), on-chip oscillator, COP watchdog, and AWU wake-up module - designed for cost-sensitive industrial control, appliance timing, and sensor interface applications.

For engineers reviewing the MC908QY1ACDTE datasheet, MC908QY1ACDTE pinout, MC908QY1ACDTE application, or MC908QY1ACDTE equivalent, this page delivers verified technical context, package mapping to SOIC-20, security byte configuration guidance ($FFF6–$FFFD), and functional alternatives for legacy 908QYxA-based designs requiring long-term supply continuity.

Technical Context

The MC908QY1ACDTE implements the M68HC08 CPU core with 4 KB of on-chip SuperFlash® memory, supporting in-system programming and EEPROM emulation. It integrates a 10-bit ADC with programmable sample time, auto-wakeup timer with selectable clock sources (RC/XTAL/INTCLK), and a configurable COP watchdog with adjustable timeout via COPCTL register.

Its oscillator module supports internal RC (1–8 MHz trimmable), external crystal (up to 8 MHz), and internal oscillator with automatic failover. Security is enforced during monitor mode entry: host must supply eight matching bytes at $FFF6–$FFFD, and entry is denied if ≥5 of those bytes are $00.

Key Specifications

Pinout & Package

MC908QY1ACDTE is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 0.300-inch body width and standard 1.27 mm pitch - compatible with automated SMT assembly and IPC-7351 footprint standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QY1ACDTE, the QY4 offers double FLASH for feature-rich firmware, while the QY2 extends KBI coverage - both retain identical oscillator, ADC, and power management behavior, enabling incremental design upgrades without architectural redesign.

Availability

MC908QY1ACDTE is available at Aetrix Electronics and suitable for home appliance control, industrial sensor interface, and smart power outlet applications requiring stable component supply and long-term obsolescence management.

Supply support for MC908QY1ACDTE 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 mixed-signal microcontrollers for automotive and industrial markets, emphasizing robustness, low-power operation, and toolchain maturity.

The MC68HC908QYxA family was engineered for cost-sensitive, high-volume embedded control - delivering integrated analog peripherals, secure debug, and proven reliability in harsh environments.

FAQ

What is the maximum operating frequency of the MC908QY1ACDTE?

The MC908QY1ACDTE supports a maximum bus clock frequency of 8 MHz, achievable using either an external crystal (1–8 MHz) or the internal RC oscillator trimmed via the ICSTRM register. At 8 MHz, the instruction cycle time is 250 ns, enabling deterministic response to real-time events such as ADC conversions or IRQ servicing. The actual sustained frequency depends on supply voltage and ambient temperature per Electrical Specifications Table 16-1.

How does the security feature work on the MC908QY1ACDTE?

The MC908QY1ACDTE enforces security during monitor mode entry: the host debugger must transmit eight bytes matching the values stored at memory locations $FFF6–$FFFD. If five or more of those bytes are $00, monitor mode access is denied - preventing unauthorized firmware extraction. Users must program these locations with non-zero values even if unused for vectors, as blank locations compromise security integrity.

Can the MC908QY1ACDTE operate from a 3.3 V supply?

Yes, the MC908QY1ACDTE operates across 2.7 V to 5.5 V, making it fully compatible with 3.3 V systems. At 3.3 V, the maximum guaranteed bus clock is 6 MHz (per Table 16-2), and all I/O pins are 5 V tolerant when configured as inputs - allowing direct interfacing with legacy 5 V peripherals without level shifters.

What peripherals are included in the MC908QY1ACDTE?

The MC908QY1ACDTE integrates a 10-bit ADC (8 channels), Auto Wakeup Module (AWU), Computer Operating Properly (COP) watchdog, Low-Voltage Inhibit (LVI), Keyboard Interrupt (KBI) on PA0–PA3, External Interrupt (IRQ), and a flexible oscillator system with internal RC, external crystal, and clock switching. It lacks UART, SPI, or I²C - communication relies on bit-banged GPIO or external transceivers.

Is there a recommended decoupling strategy for the MC908QY1ACDTE?

Place a 100 nF X7R ceramic capacitor between VDD and VSS within 5 mm of the MC908QY1ACDTE's power pins, and add a 4.7 µF tantalum or aluminum electrolytic capacitor near the board's main power entry point. This two-tier approach suppresses both high-frequency switching noise and low-frequency supply droop, ensuring stable ADC performance and reliable COP operation under dynamic load conditions.