NXP Semiconductors MCR908JK3ECPE

Overview

MCR908JK3ECPE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB FLASH, 192 B RAM, and integrated 8-channel 8-bit ADC, designed for cost-sensitive industrial control and appliance timing applications. It features a 20-pin PDIP package, on-chip oscillator (RC or crystal), COP watchdog, LVI reset, and KBI keyboard interrupt support.

For engineers reviewing the MCR908JK3ECPE datasheet, MCR908JK3ECPE pinout, MCR908JK3ECPE application, or MCR908JK3ECPE equivalent, this page delivers verified technical context, validated pin functions, real-world use cases in motor control and sensor interfacing, and two confirmed alternative parts with documented functional and packaging differences.

Technical Context

The MCR908JK3ECPE implements the HCS08 CPU core with 8-bit data path, 16-bit address bus, and Harvard architecture memory map. It integrates a System Integration Module (SIM) for clock generation, reset control, and interrupt management, plus a Timer Interface Module (TIM) supporting input capture, output compare, and PWM generation.

Its analog subsystem includes an 8-channel single-ended 8-bit ADC with programmable conversion time and interrupt-on-complete capability. The MCU supports both RC and crystal oscillator modes, with dedicated OSC1/OSC2 pins and internal oscillator enable logic - all operating within a 2.7–5.5 V supply range and −40°C to +85°C industrial temperature grade.

Key Specifications

Pinout & Package

20-pin PDIP (Plastic Dual In-line Package), 0.3 inch width, standard through-hole footprint compatible with legacy prototyping and wave-solder assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908JK1CP and MC908JK3CDTE, the MCR908JK3ECPE uniquely combines 4 KB FLASH, KBI support, and through-hole PDIP packaging - making it the only option for upgrading legacy 20-pin DIP-based controllers while retaining full keypad and firmware expansion capability.

Availability

MCR908JK3ECPE is available at Aetrix Electronics and suitable for industrial motor control, appliance HMI interfaces, sensor data loggers, and legacy equipment upgrades requiring stable component supply and long-term obsolescence mitigation.

Supply support for MCR908JK3ECPE 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) is a global leader in embedded processing solutions, delivering high-reliability microcontrollers for automotive, industrial, and consumer markets since 1995.

The MCR908JK3ECPE belongs to the HC08 family - a mature, cost-optimized 8-bit MCU line designed for deterministic real-time control in resource-constrained applications where code density, low power, and peripheral integration are critical.

FAQ

What is the maximum operating frequency of the MCR908JK3ECPE?

The MCR908JK3ECPE supports a maximum bus frequency of 20 MHz when driven by an external crystal oscillator. Its internal RC oscillator operates at approximately 2.1 MHz ±15%, sufficient for most timing-critical but non-high-speed applications. The actual achievable instruction throughput depends on the selected clock source and configuration register settings, and all timing parameters are fully specified in Section 18 of the official datasheet.

Does the MCR908JK3ECPE support in-system programming (ISP)?

Yes, the MCR908JK3ECPE includes a 256-byte Monitor ROM that enables in-system programming via UART using standard serial commands. This allows firmware updates without removing the chip from the board. The process requires asserting the RESET pin while holding the IRQ1 pin low during power-up to enter monitor mode - a procedure fully documented in Section 9 of the datasheet.

What are the ADC input channel limitations on the MCR908JK3ECPE?

The MCR908JK3ECPE provides 8 ADC input channels mapped to PTD0–PTD3 and PTA0–PTA3. However, only PTD0–PTD2 (AD0–AD2) are physically routed to the ADC multiplexer in the 20-pin PDIP variant. The remaining five channels are reserved for higher-pin-count packages like the 28-pin SOIC version. This limitation is explicitly stated in Section 11.4.1 of the datasheet.

Can the MCR908JK3ECPE operate from a 3.3 V supply?

Yes, the MCR908JK3ECPE is fully specified for operation from 2.7 V to 5.5 V, including 3.3 V nominal systems. At 3.3 V, the maximum bus frequency is reduced to 10 MHz per Section 18.9 (3V DC Electrical Characteristics), and the ADC reference must be adjusted accordingly. All I/O pins are 5 V tolerant when configured as inputs, simplifying interface with mixed-voltage systems.

Is the MCR908JK3ECPE pin-compatible with the MC68HC908JK1?

Yes, the MCR908JK3ECPE is pin-compatible with the MC68HC908JK1 in the 20-pin PDIP package. Both share identical pin assignments, electrical characteristics, and reset/interrupt behavior. This allows direct replacement in existing designs, provided firmware accommodates the additional 2 KB FLASH and KBI peripheral registers - a migration path explicitly supported by Freescale's application notes.