NXP Semiconductors MC908QY4ACDTER

Overview

MC908QY4ACDTER from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB on-chip FLASH, 192 B RAM, and integrated ADC10, AWU, COP watchdog, LVI, and keyboard interrupt modules. It operates at up to 8 MHz bus frequency, supports monitor mode programming via single-wire background interface, and features user-configurable security bytes at $FFF6–$FFFD to prevent unauthorized FLASH access. It targets low-cost industrial control and appliance timing applications requiring embedded logic with analog sensing.

For engineers reviewing the MC908QY4ACDTER datasheet, MC908QY4ACDTER pinout, MC908QY4ACDTER application, or MC908QY4ACDTER equivalent, this page delivers verified functional identity, confirmed package (TSSOP-20), validated security behavior (5+ zero-byte denial), exact memory map (4 KB FLASH/192 B RAM), and real-world use cases in motor control feedback loops and battery-powered sensor nodes.

Technical Context

The MC908QY4ACDTER implements the HCS08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing modes. Its internal oscillator provides factory-trimmed RC clock (±2% accuracy) with optional external crystal or ceramic resonator support via XTAL pins.

FLASH memory uses SuperFlash® technology enabling 100K erase/write cycles and data retention >10 years. Security enforcement occurs during monitor mode entry: host must supply eight matching bytes to $FFF6–$FFFD; if five or more are $00, entry is denied - a hardware-level protection not software-emulated.

Key Specifications

Pinout & Package

MC908QY4ACDTER is housed in a 20-pin Thin Shrink Small Outline Package (TSSOP-20) with 0.65 mm pitch, optimized for compact PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QY2ACDTER and MC908QT4ACDTER, the MC908QY4ACDTER uniquely balances 4 KB FLASH, integrated 10-bit ADC, and TSSOP-20 footprint - making it optimal for cost-sensitive mixed-signal designs where analog sensing and firmware headroom coexist.

Availability

MC908QY4ACDTER is available at Aetrix Electronics and suitable for motor control interfaces, smart appliance timers, industrial sensor nodes, and energy meter front-ends requiring stable component supply and long-term industrial lifecycle support.

Supply support for MC908QY4ACDTER 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 embedded systems, emphasizing integration, low power, and robust development tooling.

The MC908QY4ACDTER belongs to the HCS08-based QY/QTA family designed specifically for appliance control, industrial automation, and battery-operated devices needing reliable analog-digital interfacing with minimal external components.

FAQ

What is the maximum operating frequency of the MC908QY4ACDTER?

The MC908QY4ACDTER supports a maximum bus clock frequency of 8 MHz, derived from its internal RC oscillator (factory-trimmed to ±2%) or external crystal source. This frequency governs instruction execution speed, ADC conversion timing, and peripheral module operation - all timing-critical functions in real-time control applications. The MC908QY4ACDTER does not support PLL multiplication; bus speed is directly tied to oscillator source divided by configurable prescaler values.

How does the security feature of the MC908QY4ACDTER prevent unauthorized FLASH access?

The MC908QY4ACDTER enforces security during monitor mode entry by requiring eight user-defined bytes written to FLASH addresses $FFF6–$FFFD. If five or more of those bytes equal $00, monitor mode entry is denied at the hardware level. This prevents brute-force bypass attempts and ensures that blank or uninitialized security regions cannot be exploited. The MC908QY4ACDTER implements this check before any FLASH read commands execute, making it effective against both physical and logical attacks.

Can the MC908QY4ACDTER operate without an external crystal?

Yes, the MC908QY4ACDTER can operate entirely from its internal RC oscillator, which is factory-trimmed for ±2% accuracy across voltage and temperature. External crystals are optional and used only when higher timing precision is required - for example, in UART communication at 115.2 kbps or synchronous sensor sampling. The MC908QY4ACDTER automatically switches between internal and external sources based on configuration bits in the OSC module registers.

What is the role of the AWU module in low-power operation of the MC908QY4ACDTER?

The Auto Wakeup Module (AWU) in the MC908QY4ACDTER allows the device to enter stop or wait mode and autonomously resume operation after a programmable delay - using only the internal RC oscillator. This eliminates the need for external RTCs or wake-up timers, reducing system cost and power. The AWU generates interrupts at intervals from 16 ms to 4.1 s, enabling periodic sensor polling or status checks while maintaining typical stop-mode current under 1.5 µA.

Does the MC908QY4ACDTER support in-circuit programming after soldering?

Yes, the MC908QY4ACDTER supports in-circuit programming via its Background Debug Mode (BDM) interface using the BS pin. This single-wire serial protocol allows full FLASH erase, program, and verify operations without removing the device from the PCB. Development tools like P&E Micro's Cyclone or Freescale's DEMO908QY4 board provide standardized BDM headers compatible with the MC908QY4ACDTER's pinout and electrical requirements.