MC9S08RC8CFJ - 8-Bit 8MHz MCU with 8KB Flash | Motorola
MPN: MC9S08RC8CFJ ✓ ActiveMC9S08RC8CFJ Overview
An S08 microcontroller is a member of the 8-bit embedded-microcontroller hierarchy, combining a CPU core, Flash program memory, data memory, timers, communication interfaces and interrupt control in one integrated circuit. Compared with larger 16-bit or 32-bit MCU families, the MC9S08RC8CFJ provides a straightforward platform for motor control, appliance control, instrumentation and compact embedded products. Its role within an electronic system is to execute firmware, acquire external signals and coordinate actuators or communications.
The principal verified features are an 8-bit processor operating at 8 MHz, 8 KB of Flash organized as 8K x 8, and a compact 32-LQFP package. The Flash memory provides space for application code and fixed firmware, while the low pin count supports space-constrained boards. Distributor availability data identifies stocked units from multiple sources, including 33,920 pieces reported by Wolfchip on December 24, 2025, although individual inventory levels can change rapidly.
The S08 architecture is intended for embedded applications in which predictable I/O handling, compact PCB area and simple tool-supported development are more important than high computational bandwidth. The MC9S08RC8CFJ can serve as the central controller in a keypad interface, a small motor or relay controller, a sensor-processing module or a communication endpoint. Its Flash-based program model also allows firmware to be retained without an external program-memory device.
Typical applications include industrial controls, consumer appliances, automotive accessories and compact instrumentation. In each case, the MCU can read sensors through its peripheral interfaces, execute control logic and update outputs without requiring a separate processor. The 32-LQFP footprint also simplifies transition from a larger prototype package to a production board when the pin count and thermal design remain suitable.
The primary design consideration is to verify all electrical limits, pin multiplexing, clock configuration and peripheral assignments against the manufacturer datasheet before PCB release. Because the supplied verified data does not provide individual pin names, voltage limits, current ratings or memory-map details, those values are intentionally not guessed here. A reliable design should also include appropriate decoupling and a conservative operating strategy around temperature and supply-voltage limits.
This page consolidates verified distributor specifications, current pricing references, strict same-package replacement guidance, comparison parameters and practical selection notes. It is intended to help engineers distinguish verified MC9S08RC8CFJ characteristics from unconfirmed device details and to identify the information that must still be checked in the authoritative datasheet before hardware release.
Drop-in alternatives for MC9S08RC8CFJ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
MC9S08RC8CAG
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08RC8CAF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08RC8CFH
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08RC8CGJ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08RC8CJG
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08RC8CFJ Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit S08 microcontroller |
| Maximum Clock Frequency | 8 MHz |
| Flash Memory | 8 KB (8K x 8) |
| CPU Architecture | 8-bit |
| Package | 32-LQFP (7 x 7 mm) |
| Pin Count | 32 pins |
| Mounting Type | Surface mount |
| Manufacturer | Motorola |
| Product Series | S08 |
| RoHS Status | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | not_applicable |
MC9S08RC8CFJ 32-lqfp (7 x 7 mm) Pin Configuration Guide
Pin configuration for MC9S08RC8CFJ (32-lqfp (7 x 7 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for MC9S08RC8CFJ.
Refer to the datasheet for full pin configuration.
Typical Applications
MC9S08RC8CFJ is suitable for 6 applications: Compact Industrial Control, Motor and Relay Control, Appliance and User Interface Control, Sensor Conditioning and Data Acquisition, Communication Endpoint, Automotive Accessory Controller.
Compact Industrial Control
The MC9S08RC8CFJ fits compact industrial-control modules that coordinate sensors, digital inputs and actuator outputs through an embedded 8-bit MCU. Its 8 MHz operating speed supports general-purpose control logic, while the 8 KB of Flash provides space for application firmware without requiring an external memory device. The 32-LQFP 7 x 7 mm package also leaves more board perimeter than an eight-pin MCU, giving the designer access to additional pins when the selected pin multiplexing permits it. For a motor, relay or solenoid controller, validate the required timers, I/O levels and drive circuitry against the datasheet. The principal trade-off is limited code capacity relative to larger MCU families, so the firmware should be sized carefully and structured to minimize library overhead.
Recommended
Motor and Relay Control
MC9S08RC8CFJ is suitable for small motor, relay and solenoid controllers where deterministic firmware execution and compact integration matter more than application-processing performance. The 8 MHz S08 processor can execute sequencing and protection logic, while the 8 KB Flash store supports a dedicated control program. The 32-pin LQFP package can accommodate the required control and interface signals more readily than a minimal six- or eight-pin device. In the final circuit, transistor or MOSFET drive stages remain necessary because the MCU does not directly provide power amplification for motors. Verify timer channels, interrupt behavior, pin multiplexing and electrical limits in the manufacturer datasheet before selecting timing components or protection networks.
Recommended
Appliance and User Interface Control
The MC9S08RC8CFJ can serve as the controller in an appliance or embedded user interface that scans buttons, drives indicators and manages a simple display or external interface. An 8-bit MCU at 8 MHz is appropriate for finite-state-machine control, debouncing, menu logic and routine communication handling. Its 8 KB Flash limits the available code image, but that constraint can encourage a focused firmware design and avoid unnecessary abstraction. The 32-LQFP footprint supports a reasonable number of external connections in a small control board. During design, confirm which peripheral functions can be assigned simultaneously and whether the selected pins support the required 5 V or other signal levels before finalizing the schematic.
Recommended
Sensor Conditioning and Data Acquisition
MC9S08RC8CFJ is appropriate for small sensor-acquisition modules that sample external signals, apply scaling or filtering, and present results through a digital interface. The 8 MHz processing rate supports deterministic handling of low-to-moderate-bandwidth measurements, while the 8 KB Flash can hold compact acquisition and communication firmware. A 32-LQFP package provides more I/O options than the smallest MCUs, which can be helpful when a design combines sensor inputs, status outputs and communications. The exact analog and timer resources were not present in the verified excerpts, so an ADC or timer-based design must verify pin availability and conversion performance in the datasheet. Calibration data should also be included in the available nonvolatile program and data storage.
Recommended
Communication Endpoint
The MC9S08RC8CFJ can act as a compact communication endpoint for an embedded appliance, sensor node or service module. Its 8-bit S08 core is suited to protocol framing, command parsing and supervisory logic rather than high-bandwidth payload processing. The 8 MHz clock provides useful timing margin for event-driven communication, and the 8 KB Flash can hold a specialized protocol stack when the firmware is kept compact. The 32-LQFP package can expose the required serial, status and reset signals in a modest board area. Before design commitment, verify the exact serial interface, its clock requirements, pin multiplexing and electrical levels in the family datasheet. Protocol timing should also be validated at the system's worst-case clock and temperature conditions.
Recommended
Automotive Accessory Controller
MC9S08RC8CFJ may be considered for non-safety-critical automotive accessory modules where an 8-bit embedded controller and compact 32-LQFP footprint are sufficient. The 8 MHz S08 processor and 8 KB Flash can implement accessory logic, status handling and simple diagnostic functions. However, automotive production use requires strict confirmation of the suffix-specific temperature grade, qualification status, electrical limits and supply requirements from the manufacturer ordering information. The verified excerpts do not establish AEC-Q100 qualification for this exact MPN, so it should not be treated as automotive-qualified without that evidence. The safer engineering path is to use an explicitly qualified S08 ordering option and validate transient protection, EMC behavior and environmental margins during system qualification.
Recommended
Recommended Products Summary
Engineering reference data for MC9S08RC8CFJ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9S08RC8CAG | MC9S08RC8CAF | MC9S08RC8CFH | MC9S08RC8CGJ | MC9S08RC8CJG |
|---|---|---|---|---|---|---|
| Package | 32-LQFP (7 x 7 mm) | 32-LQFP (7 x 7 mm) | 32-LQFP (7 x 7 mm) | 32-LQFP (7 x 7 mm) | 32-LQFP (7 x 7 mm) | 32-LQFP (7 x 7 mm) |
| Brand | Motorola | Motorola | Motorola | Motorola | Motorola | Motorola |
| Maximum Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| CPU Architecture | 8-bit | 8-bit | 8-bit | 8-bit | 8-bit | 8-bit |
| Flash Memory | 8 KB (8K x 8) | 8 KB (8K x 8) | 8 KB (8K x 8) | 8 KB (8K x 8) | 8 KB (8K x 8) | 8 KB (8K x 8) |
| Product Series | S08 | S08 | S08 | S08 | S08 | S08 |
Key Differentiators
- Combines an 8-bit S08 processor with 8 KB of Flash in a 32-LQFP package (vs ATMEGA88A-MU)
- Uses the same verified core, memory size and clock across the proposed MC9S08RC8 drop-in family (vs MC9S08RC8CAG)
- Supports distributor availability from several independent sourcing channels (vs MC9S08RC8CJG)
Design Notes
Do not treat an identical 32-pin footprint as proof of drop-in compatibility. Before selecting MC9S08RC8CAG, MC9S08RC8CAF, MC9S08RC8CFH, MC9S08RC8CGJ or MC9S08RC8CJG, compare the manufacturer ordering table, complete pin map, supply limits, reset behavior, clock configuration and peripheral multiplexing. The verified excerpts establish the 8 MHz S08 core, 8 KB Flash and 32-LQFP format for the family, but do not expose suffix-specific temperature and qualification data.
Place the MCU close to the supporting oscillator, reset and decoupling network, and route sensitive clock and reset signals away from switching nodes and high-current actuator traces. Although the verified excerpts do not state the pin assignments, these connections are normally critical in an embedded-control design. Confirm the package land pattern and exposed versus non-exposed pad construction from the official package drawing before generating production Gerber files.
Establish the supply-voltage tolerance and I/O current limits from the MC9S08RC8 family datasheet before selecting pull-ups, level shifters or actuator drivers. A 32-pin MCU does not imply that every pin can source the same current or accept the same voltage. Use local bulk and high-frequency bypass capacitors according to the manufacturer guidance, and include a defined reset strategy for reliable startup in industrial or automotive-adjacent equipment.
The 8 KB Flash capacity is a hard design constraint that should be checked before committing to the MCU. Compile the complete production firmware, including bootloader, application code, calibration tables and library code, rather than estimating from source-code line count. The retrieved verified data does not specify RAM or EEPROM capacity, so stack and retained-data requirements also remain unresolved until the datasheet is reviewed.
Compliance Information
The verified excerpts do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free or conflict-minerals status for the exact MPN. AEC-Q100 is marked not_applicable because the verified sources do not identify this MPN as an automotive-qualified variant; an ordering variant may have different qualification requirements.