S912XET256BMAGR - 16-bit S12X MCU, 256KB Flash, 50MHz | NXP
MPN: S912XET256BMAGR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.4 | $18.40 |
| 10 | $16.3 | $163.00 |
| 100 | $14.25 | $1,425.00 |
| 500 | $12.95 | $6,475.00 |
| 1,000 | $11.75 | $11,750.00 |
S912XET256BMAGR Overview
What is an S12X MCU? The S12X is NXP's 16-bit microcontroller family, evolution of the original Freescale HC12/S12 architecture. It introduces an enhanced CPU with 32-bit internal program word width, an XGATE co-processor (a peripheral-only RISC engine) for offloading interrupt-intensive I/O, and a richer interrupt model. The S12X sits between classical 8-bit MCUs and 32-bit ARM Cortex-M parts: more deterministic than 32-bit parts yet more capable than 8-bit devices, making it a workhorse for body electronics, chassis, and powertrain-adjacent ECUs.
Key features include the XGATE co-processor that boosts overall throughput by handling virtual peripherals, a flexible hardware-emulated EEPROM subsystem for non-volatile parameter storage, and a memory protection unit with supervisor/user modes for system integrity. Communication peripherals cover CAN, SCI (UART), SPI, I2C, and IrDA, while on-chip timers include Enhanced Capture Timer (ECT), Periodic Interrupt Timer (PIT), and PWM modules. The 12-bit ADC with 3us conversion time enables precise analog monitoring for sensor conditioning.
The device integrates 119 general-purpose I/O lines, a low-voltage detector (LVD), power-on reset (POR), and a watchdog timer (WDT) to support safety-relevant designs. With 256KB of Flash, designers can run larger application stacks including AUTOSAR-compliant firmware, complex sensor fusion routines, and bootloader/OTA scaffolding without external memory.
Typical applications include automotive body control modules, HVAC and climate control ECUs, instrument clusters, lighting controllers, CAN nodes, and industrial automation gateways. The wide temperature range and AEC-Q100 qualification also make it a fit for off-road vehicles, agricultural equipment, and heavy machinery cab controllers.
When designing with the S912XET256BMAGR, allocate PCB area for the 144-LQFP footprint (0.5mm pitch), use four-layer boards with continuous ground planes under the QFP to minimize EMI, and reserve CAN bus transceivers such as the TJA1040 or TJA1057 at the connector side. Verify your toolchain (CodeWarrior, Cosmic, IAR for HCS12X) supports the XGATE co-processor if you plan to use it.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes for the S912XET256BMAGR that are not consolidated in the manufacturer datasheet.
Drop-in alternatives for S912XET256BMAGR — 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 S912XET256BMAGR (same form factor and footprint) — differing in Operating Temperature, Package, Timers, EEPROM, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
S912XET512BMAGR
✅ Drop-In✓ In Stock
$6.6 / Unit
View Datasheet →S912XET256J2VAG
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →MC9S12XEQ384CAG
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →MC9S12XDT256CAG
✅ Drop-In✓ In Stock
$17.4 / Unit
View Datasheet →MC9S12XEP768CAG
✅ Drop-In✓ In Stock
$19.85 / Unit
View Datasheet →S912XEG256J2CAL
✅ Drop-In✓ In Stock
$15.4 / Unit
View Datasheet →S912XET256BMAGR Maximum Ratings & Electrical Characteristics
| Core Processor | HCS12X |
| Core Size | 16-bit |
| Core Speed | 50 MHz |
| Program Memory Size | 256 KB (256K x 8) |
| Program Memory Type | FLASH |
| EEPROM Emulation | Yes (hardware-emulated) |
| Number of I/O | 119 |
| Package | 144-LQFP (20x20 mm, 0.5 mm pitch) |
| Mounting Type | Surface Mount |
| Connectivity | CANbus, EBI/EMI, I2C, IrDA, SCI, SPI |
| ADC | 12-bit, 3 us conversion time |
| Timers | ECT, PIT, PWM, RTI |
| Peripherals | LVD, POR, PWM, WDT |
| Co-processor | XGATE |
| Memory Protection | Yes (MPU, supervisor/user modes) |
| Operating Temperature | -40C to +125C |
| Automotive Qualification | AEC-Q100 |
| RoHS Status | Compliant |
S912XET256BMAGR 144-lqfp (20x20 mm, 0.5 mm pitch) Pin Configuration Guide
Pin configuration for S912XET256BMAGR (144-lqfp (20x20 mm, 0.5 mm pitch) 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 S912XET256BMAGR.
Refer to the datasheet for full pin configuration.
Typical Applications
S912XET256BMAGR is suitable for 6 applications: Automotive Body Control Module (BCM), HVAC Climate Control ECU, Instrument Cluster Driver, Lighting Control Module, CAN Gateway / Vehicle Network Node, Industrial Automation / Off-Highway Controller.
Automotive Body Control Module (BCM)
The S912XET256BMAGR fits body control modules because it integrates multiple CAN controllers, SCI/SPI/I2C, 119 I/O lines, and PWM outputs in a single 144-LQFP. The 256 KB Flash accommodates typical BCM firmware (central locking, wipers, lighting, mirror control) with margin for diagnostics. AEC-Q100 qualification plus -40C to +125C operation is mandatory for under-dash automotive placement. XGATE offloads high-frequency CAN message servicing so the main CPU can run the body control state machine deterministically. Designers typically pair the MCU with TJA1057 CAN transceivers and high-side switches such as the VNQ5050.
Recommended
HVAC Climate Control ECU
HVAC control ECUs require precise temperature sensing and motor actuation, which the S912XET256BMAGR supports via its 12-bit ADC (3 us conversion) and PWM channels. The 256 KB Flash holds the climate control algorithm plus sensor calibration tables, while AEC-Q100 covers the under-dash thermal environment. Hardware-emulated EEPROM stores user-setpoints and learned blower curves without external serial EEPROM. Multiple SCI/UART ports link to the infotainment head unit and rear-seat control panel. The 144-LQFP footprint and ample I/O make routing the blower, blend door, and mode motor drivers straightforward.
Recommended
Instrument Cluster Driver
Instrument clusters need fast gauge updates, CAN bus connectivity, and enough Flash for graphics bitmaps and warning logic - all of which the S912XET256BMAGR provides. The 50 MHz S12X core with XGATE handles stepper motor control loops for analog-style gauges while the main CPU drives display updates. 119 I/O lines accommodate multiplexed warning lamps and telltale LEDs without external expanders. AEC-Q100 plus -40C to +125C covers the cabin environment, where direct sun load can push PCB temperatures high. The 144-LQFP package simplifies layout against large stepper motor driver arrays.
Recommended
Lighting Control Module
Exterior and interior lighting controllers benefit from the S912XET256BMAGR's PWM channels, 119 I/O, and CAN bus interface. Adaptive headlamp, DRL, and turn-indicator patterns fit within 256 KB Flash when state machines are coded efficiently. The integrated CAN controller links the module to the body network, and hardware-emulated EEPROM stores lamp-failure counters and learned trim values. AEC-Q100 plus the wide temperature range handles under-hood and headlamp-proximity mounting. Designers typically add LIN transceivers for sub-nodes via SCI plus an external LIN phy.
Recommended
CAN Gateway / Vehicle Network Node
The S912XET256BMAGR serves well as a CAN-to-CAN gateway or bridge node, because the S12XE core integrates multiple MSCAN modules that can filter and forward frames between buses. 256 KB Flash holds the routing table and message-arbitration logic, while EBI/EMI enables external bus extension. AEC-Q100 plus -40C to +125C covers central gateway placement behind the dashboard. XGATE accelerates incoming CAN frame processing so the main CPU can apply security filters and DTC handling. Add a CAN transceiver pair such as TJA1057 at each bus interface.
Recommended
Industrial Automation / Off-Highway Controller
Off-highway and industrial applications (agricultural tractors, forklifts, construction equipment) demand the same AEC-Q100 plus -40C to +125C envelope that the S912XET256BMAGR provides. The 256 KB Flash holds PLC-style ladder logic interpreters and CANopen/J1939 stacks. 119 I/O plus PWM support sensor conditioning and hydraulic valve actuation without external expanders. The 50 MHz S12X core runs deterministic control loops at 1 ms cadence, while XGATE handles encoder counters and CAN frame bursts. The 144-LQFP package is mechanically robust for high-vibration environments.
Recommended
Recommended Products Summary
Engineering reference data for S912XET256BMAGR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | S912XET512BMAGR | S912XET256J2VAG | MC9S12XEQ384CAG | MC9S12XDT256CAG | MC9S12XEP768CAG |
|---|---|---|---|---|---|---|
| Package | 144-LQFP (MAG) | 144-LQFP (MAG) - same | 144-LQFP (MAG) - same | 144-LQFP (MAG) - same | 144-LQFP (MAG) - same | 144-LQFP (MAG) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors (Freescale legacy) | NXP Semiconductors (Freescale legacy) | NXP Semiconductors (Freescale legacy) |
| Core | HCS12X (S12XE) | HCS12X (S12XE) | HCS12X (S12XE) | HCS12X (S12XE) | HCS12X (S12XD) | HCS12X (S12XE) |
| Flash Size | 256 KB | 512 KB | 256 KB | 384 KB | 256 KB | 768 KB |
| Core Speed | 50 MHz | 50 MHz | 50 MHz | 50 MHz | 40 MHz | 50 MHz |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
| AEC-Q100 Qualified | Yes | Yes | Yes | Yes | Yes | Yes |
| Number of I/O | 119 | 119 | 119 | 119 | 119 | 119 |
| Approx. Qty-1 Price (USD) | 18.40 | ~$22.50 | ~$18.00 | ~$20.00 | ~$16.50 | ~$26.00 |
Key Differentiators
- Higher Flash density in same 144-LQFP MAG footprint (vs MC9S12XDT256CAG)
- Dual-engine S12XE architecture with XGATE co-processor (vs MC9S12XEQ384CAG (same family, 384 KB))
- Balanced Flash-to-price ratio (vs MC9S12XEP768CAG (768 KB Flash))
Design Notes
Estimated: At 50 MHz S12X core with 3.3V supply and typical 50 mA active core current, the S912XET256BMAGR dissipates roughly 0.165 W internal to silicon. The 144-LQFP package has a theta_JA around 45 C/W on a four-layer JEDEC board, giving about 7.4 C rise above ambient. Even at 125C ambient, junction stays well below the 150C automotive limit, so no heatsink is required. Still, place the MCU away from high-side driver FETs and use a continuous ground plane under the QFP to keep junction rise low under heavy I/O switching.
Route the 144-LQFP (0.5 mm pitch) with 0.20 mm trace width and 0.20 mm clearance per IPC-2222 for fine-pitch QFPs. Use a four-layer stack-up with the inner layer as a continuous ground plane and route CAN, SPI, and SCI traces over an unbroken reference. Place the VDDR/VSS decoupling pair within 3 mm of the VDDR pin, and add a 100 nF + 4.7 uF ceramic combination at each VDD pin. Use stitching vias around the QFP perimeter to reduce EMI, and keep crystal traces within 10 mm with a guard ring to ground.
Do not assume all S12X family MCUs share identical peripheral register maps - the S12XD (MC9S12XDT256CAG) versus S12XE (S912XET256BMAGR) differ in ETU/ECU timer modules and XGATE interrupt vector assignments. If porting firmware between them, recompile against the matching header file. Also, the 'E' in the part number indicates the automotive temperature grade; the standard 'C' (commercial 0C to +70C) or 'V' (extended) grades are not AEC-Q100 equivalent.
For automotive EMC compliance (CISPR 25 Class 4/5), place the S912XET256BMAGR's CAN bus traces symmetrically with respect to ground, and add a common-mode choke plus split termination (60 ohm + 60 ohm + 10 nF to ground) at each CAN connector. The 119 I/O lines are not 5V tolerant when configured for ADC; if your design mixes analog and digital signals, dedicate separate VDD/VSS pairs and place guard traces between them to suppress digital-to-analog crosstalk.
Compliance Information
RoHS compliant per NXP product page. AEC-Q100 qualified for automotive use, -40C to +125C. Lead-free finish. Conflict-minerals compliance per NXP supplier declarations.
