NXP Semiconductors MC908QY8CDTE

Overview

MC908QY8CDTE from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 8 KB on-chip FLASH, 256 B RAM, 10-bit ADC (8 channels), ESCI and SPI serial interfaces, and integrated oscillator. It operates at up to 8 MHz bus frequency and supports low-power wait/stop modes for battery-powered sensor nodes and industrial control panels.

For engineers reviewing the MC908QY8CDTE datasheet, MC908QY8CDTE pinout, MC908QY8CDTE application, or MC908QY8CDTE equivalent, this page delivers verified functional specifications, security byte handling in monitor mode, I/O port mapping, and direct replacement guidance for legacy HC08-based designs requiring long-term supply continuity.

Technical Context

The MC908QY8CDTE implements the M68HC08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing. Its memory map includes 8 KB FLASH (with block protection and mass erase), 256 B RAM, and 64 B EEPROM-like register space. The internal oscillator provides stable clocking without external crystals, configurable via trim register.

Security is enforced during monitor mode entry: host must send eight user-defined bytes matching locations $FFF6–$FFFD; entry is denied if five or more are zero. The device integrates ESCI (UART/LIN-capable), SPI, 8-channel 10-bit ADC, Auto Wakeup Module (AWU), COP watchdog, and LVI reset circuitry - all operating under a unified SIM module.

Key Specifications

Pinout & Package

MC908QY8CDTE is housed in a 28-pin SOIC package (SO-28) with 24 general-purpose I/O pins, 2 oscillator pins (OSC1/OSC2), 1 reset (RES), 1 IRQ, and power/ground terminals. Pin functions are multiplexed via configuration registers and support priority-based assignment per pin.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QY4CDTE and MC908QY8CFUE, the MC908QY8CDTE uniquely balances SOIC manufacturability, 8 KB field-upgradable FLASH, and LIN-ready ESCI - making it optimal for cost-sensitive, space-constrained embedded control where long-term availability and toolchain continuity matter.

Availability

MC908QY8CDTE is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body electronics, legacy equipment upgrades, and smart appliance control requiring stable component supply over 10+ year production lifecycles.

Supply support for MC908QY8CDTE 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 automotive and industrial markets, emphasizing robustness, longevity, and toolchain stability.

The MC908QY8CDTE belongs to the M68HC08 family designed for cost-sensitive, low-power embedded control applications where deterministic real-time behavior and long-term component availability are mandatory.

FAQ

What is the maximum bus frequency supported by the MC908QY8CDTE?

The MC908QY8CDTE supports a maximum bus frequency of 8 MHz. This is derived from its internal oscillator or external crystal source, divided appropriately by the system integration module (SIM). At 8 MHz, the device achieves sufficient throughput for real-time ADC sampling, ESCI UART communication at 115.2 kbps, and responsive GPIO control - all while maintaining compatibility with legacy HC08 development tools and debug probes.

How does the security feature work during monitor mode entry for the MC908QY8CDTE?

The MC908QY8CDTE enforces security during monitor mode entry by requiring the host to transmit eight bytes matching the user-programmed values stored at memory addresses $FFF6–$FFFD. If five or more of those bytes are zero, monitor mode entry is denied. This prevents unauthorized FLASH memory reads during debugging or programming, ensuring firmware intellectual property remains protected even when the device is physically accessible.

Does the MC908QY8CDTE include an integrated oscillator, and can it operate without external components?

Yes, the MC908QY8CDTE includes an integrated RC oscillator that can operate without external components. It is factory-trimmed and further adjustable via the internal oscillator trim register (INTOSC) to achieve ±2% accuracy across voltage and temperature. This allows full functionality - including ADC conversions, ESCI communication, and COP watchdog operation - using only VDD and VSS connections, reducing bill-of-materials cost and PCB area.

Which serial communication protocols are supported by the MC908QY8CDTE's ESCI module?

The ESCI module in the MC908QY8CDTE supports UART (asynchronous serial) and LIN 1.3 physical layer communication. It implements precise bit timing, break detection, and sync field recognition required for LIN slave operation. While not a full protocol stack, the hardware-level timing compliance enables seamless integration into automotive body networks when paired with appropriate LIN software drivers.

Is the MC908QY8CDTE pin-compatible with other members of the MC68HC908QY family?

Yes, the MC908QY8CDTE is pin-compatible with the MC908QY4CDTE and MC908QY2CDTE within the same SO-28 package variant. All share identical pin assignments for PORTA, PORTB, PORTC, OSC1/OSC2, RES, IRQ, and power terminals. Firmware and PCB layouts designed for one can be reused across the family, differing only in FLASH/RAM capacity and certain fuse-configured features - enabling scalable design reuse.