NXP Semiconductors MC908QC8VDRE

Overview

MC908QC8VDRE from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 8 KB on-chip FLASH, 256 B RAM, and integrated peripherals including ADC10, ESCI, SPI, TIM1/TIM2, KBI, and COP watchdog. It operates at up to 8 MHz bus frequency, supports 3.3 V and 5 V supply, and targets embedded control in industrial sensors and appliance subsystems.

For engineers reviewing the MC908QC8VDRE datasheet, MC908QC8VDRE pinout, MC908QC8VDRE application, or MC908QC8VDRE equivalent, this page delivers verified functional identity, validated package mapping (28-pin TSSOP), confirmed security byte validation logic ($FFF6–$FFFD), real-world low-power mode behavior (STOP/WAIT), and cross-referenced alternative MCU options for legacy 08-family migration paths.

Technical Context

The MC908QC8VDRE implements the M68HC08 CPU core with 16-bit address space, 8-bit data path, and Harvard architecture memory organization. It integrates a 10-bit successive-approximation ADC (ADC10) with 8 input channels, programmable conversion clock, and dedicated VREFH/VREFL pins - enabling precision analog sensing without external references.

Its oscillator system supports internal RC, external crystal (XTAL), or external clock input, with BUSCLKX4 and BUSCLKX2 outputs for peripheral timing. The enhanced serial communications interface (ESCI) provides full-duplex asynchronous communication with programmable baud rate generation and break detection - suitable for host-to-peripheral command links in constrained systems.

Key Specifications

Pinout & Package

MC908QC8VDRE is housed in a 28-pin Thin Shrink Small Outline Package (TSSOP), measuring 9.7 mm × 4.4 mm × 1.2 mm, with 0.65 mm lead pitch and exposed thermal pad (non-electrical). This RoHS-compliant package supports automated SMT assembly and moderate power dissipation in space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QC8VDRE, MC908QC16VDRE offers immediate scalability within identical hardware, while S9KEAZ128AMLH demands redesign but delivers 6× higher MIPS and long-term roadmap viability - making the former ideal for incremental upgrades and the latter for greenfield projects.

Availability

MC908QC8VDRE is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance control units, motor drive subsystems, and energy metering modules requiring stable component supply across extended production lifecycles.

Supply support for MC908QC8VDRE 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 microcontrollers for cost-sensitive, reliability-critical embedded systems - delivering silicon with robust ESD tolerance, wide temperature range, and automotive-grade qualification.

The MC908QC8VDRE belongs to the M68HC08 family, designed specifically for resource-constrained industrial and consumer control applications where deterministic real-time response, low power, and long-term availability outweigh raw performance.

FAQ

What is the maximum bus frequency supported by the MC908QC8VDRE?

The MC908QC8VDRE supports a maximum bus frequency of 8 MHz. This defines the base timing for all CPU instructions and peripheral modules - for example, a 1 μs timer tick requires BUSCLKX4 = 32 MHz, meaning the internal oscillator or external crystal must be configured accordingly. The actual achievable frequency depends on supply voltage and ambient temperature per electrical specifications in Rev. 5 datasheet Section 19.

Does the MC908QC8VDRE include hardware support for EEPROM emulation?

Yes, the MC908QC8VDRE supports EEPROM emulation using its on-chip 8 KB SuperFlash® memory. Freescale provides application notes (e.g., AN2214) detailing wear-leveling algorithms and sector management routines that enable reliable nonvolatile data storage with 100K+ write cycles - essential for logging calibration data or user preferences without external memory.

How does the security feature prevent unauthorized access to FLASH contents?

The MC908QC8VDRE's security feature blocks monitor mode entry unless eight user-defined bytes programmed at memory locations $FFF6–$FFFD match those sent by the host during debug initialization. An added safeguard denies access if five or more of those bytes are zero - preventing accidental exposure due to unprogrammed security fields. This protects firmware IP during field servicing or third-party repair.

Can the MC908QC8VDRE operate from a 3.3 V supply while maintaining full peripheral functionality?

Yes, the MC908QC8VDRE is fully specified for 3.3 V operation across its entire temperature range (–40°C to +105°C), including all peripherals: ADC10, ESCI, SPI, TIM1/TIM2, and KBI. Electrical characteristics such as ADC offset error, ESCI baud rate accuracy, and GPIO drive strength are guaranteed at 3.3 V per Section 19.8 of the Rev. 5 datasheet - enabling direct integration with modern low-voltage logic families.

What are the key differences between the MC908QC8VDRE and MC908QC16VDRE?

The MC908QC8VDRE and MC908QC16VDRE share identical pinout, package, peripheral set, and instruction set - differing only in FLASH capacity (8 KB vs. 16 KB) and RAM (256 B vs. 512 B). Firmware compiled for MC908QC8VDRE runs unchanged on MC908QC16VDRE, making the latter a drop-in upgrade path for applications requiring larger code space or dual-bank firmware updates.