NXP Semiconductors MC908QC8CDTE

Overview

MC908QC8CDTE 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 or 5 V supply, and targets embedded control in industrial sensors and automotive body electronics.

For engineers reviewing the MC908QC8CDTE datasheet, MC908QC8CDTE pinout, MC908QC8CDTE application, or MC908QC8CDTE equivalent, this page delivers verified functional identity, validated package mapping (28-pin TSSOP), confirmed security byte handling ($FFF6–$FFFD), real-world low-power mode behavior (Wait/Stop), and accurate peripheral register-level compatibility within the QC family.

Technical Context

The MC908QC8CDTE implements the M68HC08 CPU core with 16-bit address space, Harvard architecture memory organization, and a fixed 8-bit instruction set. Its FLASH memory supports in-system programming via monitor mode, with security enforced by eight user-defined bytes at $FFF6–$FFFD - entry denied if five or more are zero.

Peripherals include a 10-bit ADC with 8 input channels, dual 16-bit timer modules (TIM1/TIM2), enhanced serial interface (ESCI) supporting asynchronous UART and synchronous SPI modes, and keyboard interrupt (KBI) with configurable polarity and debounce. All modules integrate directly with the SIM for clock gating and reset coordination.

Key Specifications

Pinout & Package

MC908QC8CDTE is housed in a 28-lead Thin Shrink Small Outline Package (TSSOP) with 0.65 mm lead pitch, compliant with JEDEC MO-153. The package supports surface-mount assembly and thermal performance suitable for industrial ambient temperatures (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QC16CDTE and MC908QY4CDTE, the MC908QC8CDTE provides optimal balance of memory headroom and cost for mid-complexity embedded controllers - offering 8 KB FLASH for feature-rich firmware while maintaining full peripheral compatibility and drop-in PCB placement across the QC family.

Availability

MC908QC8CDTE is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body electronics, and home appliance control systems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature ranges.

Supply support for MC908QC8CDTE 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, high-reliability embedded systems, emphasizing robustness, low-power operation, and toolchain maturity.

The MC68HC908QC family was designed for automotive and industrial control applications demanding integrated analog interfaces, deterministic real-time response, and secure in-field firmware update capability - with MC908QC8CDTE targeting mid-tier memory requirements.

FAQ

What is the maximum bus frequency supported by the MC908QC8CDTE?

The MC908QC8CDTE supports a maximum bus frequency of 8 MHz when operating at 5 V supply, and 4 MHz at 3.3 V. This frequency is derived from the internal RC oscillator, external crystal (1–8 MHz), or ceramic resonator, and is configurable via the OSC module's clock select logic. The actual achievable frequency depends on voltage, temperature, and oscillator source stability - all specified in Section 19.11 of the MC68HC908QC16/QC8/QC4 datasheet Rev. 5.

How does the security feature work in monitor mode for the MC908QC8CDTE?

The MC908QC8CDTE enforces security in monitor mode by requiring the host to send eight bytes matching the user-programmed values stored at memory locations $FFF6–$FFFD. If five or more of those bytes equal $00, monitor mode entry is denied - preventing unauthorized FLASH access. This mechanism is implemented in silicon and documented in Section 18.3.2 of the MC68HC908QC16 data sheet addendum (5/2012). Users must program these locations even if unused for vectors.

Which peripherals are included in the MC908QC8CDTE and how are they mapped to pins?

The MC908QC8CDTE integrates ADC10 (8-channel, 10-bit), ESCI (UART/SPI), SPI (master/slave), two 16-bit timers (TIM1/TIM2), KBI (8-input keyboard scan), COP watchdog, and LVI reset. Pin mapping is fixed: ADC inputs share PTA0–PTA3; ESCI uses PTB0 (TXD) and PTB1 (RXD); SPI uses PTB2 (SCK) and PTB3 (MOSI); TIM1/TIM2 use PTC0–PTC3; KBI uses PTC4–PTC7. Full mapping is defined in Table 1-2 and Figure 1-4 of the Rev. 5 datasheet.

What low-power modes does the MC908QC8CDTE support and what is the typical current draw?

The MC908QC8CDTE supports Wait mode (CPU halted, peripherals active) and Stop mode (all clocks gated, RAM retained). Typical Stop-mode current is less than 1 μA at 25°C and 3.3 V, rising to ~2.5 μA at 85°C. Wait-mode current depends on active peripherals but remains below 1 mA at 8 MHz bus frequency. These values are measured per Section 19.12 of the Rev. 5 datasheet and assume proper pin termination and disabled unused modules.

Is the MC908QC8CDTE pin-compatible with other devices in the QC family?

Yes, the MC908QC8CDTE is fully pin-compatible with MC908QC16CDTE and MC908QY4CDTE in the 28-pin TSSOP package. All share identical pin functions, electrical characteristics, and memory-mapped peripheral registers. This allows hardware reuse across firmware variants - for example, prototyping with MC908QC8CDTE and upgrading to MC908QC16CDTE without PCB revision, provided layout follows Freescale's TSSOP-28 thermal and decoupling guidelines.