NXP Semiconductors MC908JK1ECDWE

Overview

MC908JK1ECDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller featuring 1 KB on-chip FLASH, 64 bytes RAM, and a 10-bit ADC with 4 input channels. It operates at up to 8 MHz bus frequency, supports low-power Wait/Stop modes, and integrates TIM, KBI, COP, LVI, and serial monitor ROM for embedded control in cost-sensitive industrial and consumer systems.

For engineers reviewing the MC908JK1ECDWE datasheet, MC908JK1ECDWE pinout, MC908JK1ECDWE application, or MC908JK1ECDWE equivalent, this page delivers verified electrical specs, package mapping, functional role in sensor interface and motor control, and validated alternative options for design continuity and sourcing resilience.

Technical Context

The MC908JK1ECDWE implements the M68HC08 CPU core with 16-bit address space, Harvard architecture memory organization, and a System Integration Module (SIM) managing clock generation, reset sequencing, and interrupt prioritization. Its oscillator supports crystal (XTALCLK) or internal RC (RCCLK) sources, with configurable startup timing and Stop/Wait mode clock gating.

Peripheral integration includes a 2-channel Timer Interface Module (TIM) supporting input capture, output compare, and PWM; a Keyboard Interrupt Module (KBI) for matrix scanning; and a Monitor ROM enabling in-system programming via UART without external debugger. All peripherals are register-mapped into the I/O space and share common interrupt vectors via the SIM.

Key Specifications

Pinout & Package

MC908JK1ECDWE is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 300 mil body width, compliant with JEDEC MS-013AC. Pin pitch is 0.050 inch (1.27 mm), and thermal resistance θ_JA is 130°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908JK1ECDWE, the JK3 offers double FLASH/RAM for feature-rich firmware, while the JL3 provides pin-compatible I/O expansion-both retain identical instruction set, peripheral registers, and development tool compatibility, enabling seamless migration paths.

Availability

MC908JK1ECDWE is available at Aetrix Electronics and suitable for industrial sensor nodes, small appliance control, and motor speed regulation requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MC908JK1ECDWE 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 control, emphasizing integration, low power, and toolchain maturity.

The MC908JK1ECDWE belongs to the HCS08 family designed for ultra-low-cost, high-reliability applications in white goods, industrial controls, and automotive body electronics where minimal footprint and robustness are critical.

FAQ

What is the maximum operating frequency of the MC908JK1ECDWE?

The MC908JK1ECDWE supports a maximum bus frequency of 8 MHz, derived from its internal oscillator or external crystal source. This frequency determines instruction execution speed and peripheral timing resolution; actual system clock is divided from the oscillator by the SIM's prescaler, and timing-critical applications must account for bus cycle overhead in TIM and ADC configurations. The MC908JK1ECDWE maintains full functionality across its specified voltage range (2.7–5.5 V) at this rate.

Does the MC908JK1ECDWE include a hardware watchdog timer?

Yes, the MC908JK1ECDWE integrates a Computer Operating Properly (COP) module functioning as a programmable watchdog timer. It features a 15-bit down-counter with selectable timeout intervals ranging from 0.5 ms to 1.6 s, resettable only by writing a specific key sequence to the COPCTL register. If the firmware fails to service it before timeout, the COP asserts a hardware reset-ensuring recovery from infinite loops or hangs. This function is active in all modes except Stop mode.

Can the MC908JK1ECDWE perform in-system programming without external hardware?

Yes, the MC908JK1ECDWE contains 256 bytes of Monitor ROM that enables UART-based in-system programming (ISP) without requiring a dedicated programmer or debug probe. By asserting the RESET pin while holding IRQ low, the device enters monitor mode and accepts commands to erase, program, and verify FLASH memory over a standard serial interface. This capability is fully implemented in silicon and requires no external components beyond the UART transceiver.

What ADC resolution and input count does the MC908JK1ECDWE support?

The MC908JK1ECDWE integrates a 10-bit successive-approximation ADC with four selectable analog input channels (AN0–AN3), mapped to PTA0–PTA3. Conversion time is fixed at 12 µs per sample under typical conditions, and the ADC uses the internal bandgap reference for accuracy. Input voltage range is 0–VDD, and the module supports both single-conversion and continuous modes, with interrupt generation upon completion. No external reference or sample-and-hold capacitor is required.

Is the MC908JK1ECDWE pin-compatible with other members of the JKx family?

The MC908JK1ECDWE shares the same 20-pin SOIC footprint and pin assignments with the MC908JK3ECDWE, making them mechanically and electrically pin-compatible. Both devices use identical I/O mappings, peripheral register layouts, and reset/power sequencing-allowing direct substitution where firmware fits within 1 KB FLASH. However, the JK3's larger memory does not alter pin function, so existing PCBs designed for MC908JK1ECDWE can accommodate the JK3 without layout changes.