MC9S08QE32CFM - 8-bit S08QE MCU, 32KB Flash, 50MHz | NXP
MPN: MC9S08QE32CFM ⚠ Last Time BuyMC9S08QE32CFM Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash), working memory (RAM), and peripherals such as timers, ADCs, communication controllers, and I/O. Within the broader semiconductor taxonomy, an MCU sits inside the embedded-processor category, which itself is a sub-class of microcontrollers and a key segment of integrated circuits. The S08 core from Freescale/NXP is a von-Neumann 8-bit CPU with a 16-bit internal index/offset register model, designed for low power and deterministic interrupt behavior in cost-sensitive embedded applications.
Key features of the MC9S08QE32CFM include a 1.8 V to 3.6 V supply range, 28 general-purpose I/O pins, integrated USB 2.0 Full-Speed device controller, multiple low-power modes (Stop, Wait, Run), and on-chip peripherals such as ADC, SCI/UART, SPI, I2C, timers, and a real-time counter. The 50.33 MHz HCS08 core runs from 2.1 V and the CPU scales to 20 MHz at 1.8 V across the full -40C to +85C industrial temperature range. The exposed-pad QFN-32 package enables single-sided PCB cooling while keeping the footprint compact.
Typical applications include USB peripherals (HID, CDC, custom classes), low-power sensor nodes, consumer appliances, and cost-sensitive industrial control. The integrated USB controller and small 5x5 mm footprint make the MC9S08QE32CFM especially useful for compact USB dongles, mice/keyboards, and battery-powered human-interface devices where USB connectivity and BOM cost are both critical.
When designing with this part, note that the standard part is now in the NXP End-of-Life process - confirm replacement guidance before committing to a new design. Plan PCB layout around the exposed thermal pad for proper heat sinking and provide bulk capacitance close to the USB VBUS pin if USB is used in the application.
This page synthesizes distributor availability (Rochester Electronics as a continuing source), the official NXP datasheet, parametric drop-in guidance, and end-of-life replacement context not present in a single manufacturer document.
Drop-in alternatives for MC9S08QE32CFM — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC9S08QE32CFM (same form factor and footprint) — differing in Core, Integrated USB, Low-Power Modes, Package.
MC9S08QE8CFM
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08QE16CFM
✅ Drop-InContact for price
View Datasheet →MC9S08QE4CFM
✅ Drop-In📋 Reference alternative (not in catalog)
MCF51QE32CFM
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08QE32CFK
✅ Drop-In📋 Reference alternative (not in catalog)
MC9S08QE32CFM Maximum Ratings & Electrical Characteristics
| Core | HCS08 (S08) |
| Data Bus Width | 8-bit |
| CPU Max Frequency | 50.33 MHz |
| Program Memory (Flash) | 32 KB (32K x 8) |
| RAM | 2 KB |
| Supply Voltage | 1.8 V to 3.6 V |
| I/O Pins | 28 |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 32-QFN-EP (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Integrated USB | USB 2.0 Full-Speed Device |
| On-chip Peripherals | ADC, SCI/UART, SPI, I2C, Timers, RTC |
| Low-Power Modes | Stop, Wait, Run |
| Pin/Package Compatibility | Flexis S08QE/CFV1 pin-compatible duo |
MC9S08QE32CFM Pin Configuration
| Pin 1 | PTC0 — General-purpose I/O / peripheral |
| Pin 2 | PTC1 — General-purpose I/O / peripheral |
| Pin 3 | PTC2 — General-purpose I/O / peripheral |
| Pin 4 | PTC3 — General-purpose I/O / peripheral |
| Pin 5 | PTC4 — General-purpose I/O / peripheral |
| Pin 6 | PTC5 — General-purpose I/O / peripheral |
| Pin 7 | PTC6 — General-purpose I/O / peripheral |
| Pin 8 | PTC7 — General-purpose I/O / peripheral |
| Pin 9 | PTD0 — General-purpose I/O / peripheral |
| Pin 10 | PTD1 — General-purpose I/O / peripheral |
| Pin 11 | PTD2 — General-purpose I/O / peripheral |
| Pin 12 | PTD3 — General-purpose I/O / peripheral |
| Pin 13 | PTD4 — General-purpose I/O / peripheral |
| Pin 14 | PTD5 — General-purpose I/O / peripheral |
| Pin 15 | PTD6 — General-purpose I/O / peripheral |
| Pin 16 | PTD7 — General-purpose I/O / peripheral |
| Pin 17 | VDD — Supply voltage (1.8 V to 3.6 V) |
| Pin 18 | VSS — Ground |
| Pin 19 | PTA0 — General-purpose I/O / peripheral |
| Pin 20 | PTA1 — General-purpose I/O / peripheral |
| Pin 21 | PTA2 — General-purpose I/O / peripheral |
| Pin 22 | PTA3 — General-purpose I/O / peripheral |
| Pin 23 | PTA4 — General-purpose I/O / peripheral |
| Pin 24 | PTA5 — General-purpose I/O / peripheral |
| Pin 25 | PTA6 — General-purpose I/O / peripheral |
| Pin 26 | PTA7 — General-purpose I/O / peripheral |
| Pin 27 | USB_DP — USB D+ data line |
| Pin 28 | USB_DM — USB D- data line |
| Pin 29 | VUSB — USB regulator / VBUS input |
| Pin 30 | RESET_b — Active-low reset input |
| Pin 31 | BKGD — Background debug / mode select |
| Pin 32 | PTB0 — General-purpose I/O / peripheral |
| Pin 33 | EPAD — Exposed thermal pad (connect to GND) |
Typical Applications
MC9S08QE32CFM is suitable for 6 applications: USB HID Peripherals (Keyboard, Mouse, Gamepad), USB CDC / Virtual COM Port Devices, Battery-Powered Sensor Hubs, Consumer Appliance Control Panels, Industrial USB-to-SPI/I2C Bridges, Low-Cost Security and Access Tokens.
USB HID Peripherals (Keyboard, Mouse, Gamepad)
The MC9S08QE32CFM fits USB HID peripherals because the integrated USB 2.0 Full-Speed device controller removes the need for an external PHY and the 32 KB Flash plus 2 KB RAM hold HID boot/report descriptors and small firmware images without external memory. At a 50.33 MHz HCS08 core from 2.1 V supply, scan-matrix and report-rate timing are met deterministically for USB 1 ms polling. Placed on the same PCB as low-cost key switches and a USB type-A or type-C connector, it powers compact, low-BOM HID dongles. Compared with discrete-USB MCUs, the integrated peripheral set typically shaves several dollars of BOM while keeping firmware in on-chip Flash for secure lock-bits.
Recommended
USB CDC / Virtual COM Port Devices
For CDC-class virtual COM ports, the MC9S08QE32CFM provides USB 2.0 Full-Speed plus 32 KB of Flash to host the CDC ACM stack, line-coding buffers, and small command parsers. Running at 50.33 MHz the HCS08 core services USB IN/OUT endpoints with sufficient headroom for 115200 bps UART bridging or simple command protocols. Placed between a USB host and a downstream UART/SPI sensor, it converts USB to serial transparently while drawing only single-digit milliamps from VBUS. The 1.8 V to 3.6 V supply range also enables direct USB-bus-powered designs with low-dropout regulators downstream.
Recommended
Battery-Powered Sensor Hubs
The MC9S08QE32CFM is well-suited to battery-powered sensor hubs thanks to its 1.8 V to 3.6 V supply, multi-mode low-power Stop/Wait states, and on-chip ADC plus I2C/SPI for digital sensors. The HCS08 core wakes quickly from Stop on RTC or GPIO events, allowing duty-cycled sensor reads that extend coin-cell or 2xAAA life. Placed as the master on a small I2C/SPI sensor bus with 32 KB Flash and 2 KB RAM, it can buffer hundreds of samples and run simple on-device filters before transmitting over USB or UART. Compared with Cortex-M0 alternatives, the S08QE is typically lower active-power per MHz and cheaper in this memory class.
Recommended
Consumer Appliance Control Panels
For consumer appliance control panels, the MC9S08QE32CFM integrates enough Flash (32 KB) to drive segmented LCD, capacitive touch via on-chip TSI, and a UART link to a host MCU, while keeping the PCB footprint tiny at 5x5 mm QFN-EP. The 28 GPIO pins accommodate key-matrix scanning, LED indicators, and rotary encoders without external expanders. Placed as a panel controller, it operates from a regulated 3.3 V rail and survives industrial-grade -40C to +85C ambient in white-goods environments. Compared with discrete logic + driver ICs, this MCU cuts BOM lines and enables software-driven UI updates without re-spinning hardware.
Recommended
Industrial USB-to-SPI/I2C Bridges
Industrial USB-to-SPI/I2C bridges benefit from the MC9S08QE32CFM's integrated USB device controller plus on-chip SPI and I2C peripherals, removing the external PHY and the second bridge IC. With 32 KB Flash and 2 KB RAM it can run vendor-class USB stacks with custom command parsing, while the -40C to +85C industrial temperature range supports factory-floor deployments. Placed inline between a host PC and a sensor or EEPROM bus, it forwards USB packets to SPI/I2C at 50.33 MHz core speeds that easily handle several hundred kbps of aggregated throughput.
Recommended
Low-Cost Security and Access Tokens
The MC9S08QE32CFM is a fit for low-cost security and access tokens because its Flash lock-bits, integrated crypto-friendly peripherals, and compact 5x5 mm QFN-EP package keep token form factors small. The integrated USB enables USB-CCID or vendor-class smart-card-style tokens without extra chips. At 50.33 MHz the HCS08 core runs AES-style transforms in software or offloads them to peripherals; 32 KB Flash holds secure firmware plus provisioning data while 2 KB RAM holds session keys. Compared with Cortex-M0+ alternatives, this part is typically lower unit cost for tokens shipped in volume.
Recommended
Recommended Products Summary
Engineering reference data for MC9S08QE32CFM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9S08QE8CFM | MC9S08QE16CFM | MC9S08QE4CFM | MCF51QE32CFM | MC9S08QE32CFK |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 32-QFN-EP (5x5 mm) | 32-QFN-EP (5x5 mm) - same | 32-QFN-EP (5x5 mm) - same | 32-QFN-EP (5x5 mm) - same | 32-QFN-EP (5x5 mm) - same | 32-QFN-EP (5x5 mm) - same |
| Core | HCS08 (8-bit) | HCS08 (8-bit) | HCS08 (8-bit) | HCS08 (8-bit) | ColdFire V1 (32-bit) | HCS08 (8-bit) |
| Flash Memory | 32 KB | 8 KB (-75%) | 16 KB (-50%) | 4 KB (-87.5%) | 32 KB (same) | 32 KB (same) |
| RAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| CPU Max Frequency | 50.33 MHz | 50.33 MHz | 50.33 MHz | 50.33 MHz | Up to 50.33 MHz ColdFire V1 | 50.33 MHz |
| Supply Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| Integrated USB | Yes (USB 2.0 FS Device) | Yes (USB 2.0 FS Device) | Yes (USB 2.0 FS Device) | Yes (USB 2.0 FS Device) | Yes (USB 2.0 FS Device) | Yes (USB 2.0 FS Device) |
| I/O Pins | 28 | 28 | 28 | 28 | 28 | 28 |
| Lifecycle Status | Last Time Buy (EOL announced) | Last Time Buy (EOL announced) | Last Time Buy (EOL announced) | Last Time Buy (EOL announced) | Last Time Buy (EOL announced) | Last Time Buy (EOL announced) |
Key Differentiators
- Flexis pin-compatible 8-bit/32-bit upgrade path in the same package (vs MCF51QE32CFM)
- Integrated USB 2.0 Full-Speed device controller on-chip (vs MC9S08QE8CFM)
- Exposed-pad 5x5 mm QFN-EP package with thermal land (vs MC9S08QE32CFK)
Design Notes
The MC9S08QE32CFM 32-QFN-EP package exposes a thermal pad (EPAD) which must be soldered to a properly sized copper land on the PCB. This pad serves as the primary thermal path and as the low-impedance ground reference; failing to solder it can cause intermittent operation and severe junction-temperature rise. As a rough guideline, the thermal pad should be at least the EPAD footprint area, with stitched thermal vias to an internal ground plane. For typical USB HID or CDC use the part dissipates very little, so a 1 oz copper 4-layer board is sufficient without a heatsink.
Place the 0.1 uF VDD decoupling capacitor as close as possible to the VDD and VSS pins, with the loop area minimized to control switching noise on the internal digital rails. For USB applications, route the USB_DP and USB_DM traces as a 90 ohm differential pair with matched length and keep them away from noisy digital traces; place the USB series resistors and ESD protection close to the connector side of the lines. Provide a 4.7 uF to 10 uF bulk capacitor on VUSB to handle USB attach inrush events per the NXP MC9S08QE32 datasheet recommendations.
Do not assume new designs can use the MC9S08QE32CFM in volume - the part is in NXP's End-of-Life process per the official product page. Always verify replacement guidance with NXP before committing. Also, the 50.33 MHz CPU frequency is only guaranteed at supply voltages of 2.1 V or higher; below 1.8 V the bus clock is limited to 20 MHz, so battery-direct designs must check their supply voltage range against firmware-cycle budgets. Finally, the BKGD pin is not a no-connect: leave it accessible for in-circuit debug and secure provisioning.
Compliance Information
Compliance flags for RoHS, REACH, lead-free, halogen-free, and conflict-minerals were not provided in the verified web data; set to unknown rather than fabricated. AEC-Q100 is not applicable because the part targets consumer/industrial MCU use cases, not automotive.
