NXP Semiconductors MC9S12A256BCFU

Overview

MC9S12A256BCFU from Freescale Semiconductor is a 16-bit HCS12 microcontroller featuring 256 KB on-chip Flash EEPROM, 12 KB RAM, and integrated CAN 2.0B controller, ATD10 (10-bit, 16-channel ADC), 8-channel PWM, and enhanced capture timer - deployed in automotive engine control units and industrial motor drive firmware.

For engineers reviewing the MC9S12A256BCFU datasheet, MC9S12A256BCFU pinout, MC9S12A256BCFU application, or MC9S12A256BCFU equivalent, this page delivers verified electrical specs, package mapping to 112-pin LQFP, functional pin roles, real-world use cases in powertrain systems, and two validated alternative parts with documented technical differences.

Technical Context

The MC9S12A256BCFU implements the HCS12 CPU core with 16-bit data path, 24-bit addressing, and background debug mode (BDM) support. It integrates a PLL-based clock generator enabling bus frequencies up to 25 MHz, and supports multiple low-power modes including Stop, Wait, and Pseudo-Stop.

Its memory subsystem includes 256 KB of user-programmable Flash with EEPROM emulation, 12 KB of SRAM, and 4 KB of EEPROM. Peripheral integration includes dual SCI, dual SPI, I²C, MSCAN, ATD0/ATD1 (dual 10-bit ADCs), and 8-channel PWM with center-aligned capability.

Key Specifications

Pinout & Package

MC9S12A256BCFU is housed in a 112-pin LQFP (Low-Profile Quad Flat Package) with 0.4 mm pitch, case number 987, thermal resistance θ_JA = 32°C/W. Pin assignments follow the standard MC9S12DP256B-compatible layout per Figure 2-1 of the Device User Guide.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9S12A256BCFU, both alternatives offer larger memory and enhanced thermal/ESD robustness but require PCB layout revision due to different pinouts and voltage regulator requirements - neither is pin-compatible.

Availability

MC9S12A256BCFU is available at Aetrix Electronics and suitable for automotive powertrain control, industrial motor drives, body electronics, and telematics gateway applications requiring stable component supply and long-term industrial availability.

Supply support for MC9S12A256BCFU 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) specialized in automotive and industrial microcontrollers, delivering high-reliability silicon for safety-critical embedded systems.

The MC9S12A256BCFU belongs to the HCS12 family, designed specifically for cost-sensitive, real-time automotive applications demanding CAN connectivity, analog signal acquisition, and deterministic control loop execution.

FAQ

What is the maximum bus frequency supported by the MC9S12A256BCFU?

The MC9S12A256BCFU supports a maximum bus frequency of 25 MHz, achieved using its internal PLL with an external crystal (1–8 MHz) or clock source. This frequency governs instruction execution speed, peripheral timing, and interrupt latency - critical for meeting hard real-time deadlines in engine control applications where the MC9S12A256BCFU is commonly deployed.

Does the MC9S12A256BCFU include on-chip Flash security features?

Yes, the MC9S12A256BCFU implements Flash security via a dedicated security byte in the Flash configuration field. When enabled, it prevents external read access to Flash contents through BDM or other interfaces. Unsecuring requires a full chip erase, ensuring firmware intellectual property protection - a key requirement in automotive ECUs using the MC9S12A256BCFU.

How many CAN controllers does the MC9S12A256BCFU integrate?

The MC9S12A256BCFU integrates one MSCAN module compliant with CAN 2.0B specification, supporting up to 15 message buffers, programmable identifier filtering, and automatic retransmission. While some derivatives like MC9S12DP256B share this single-CAN architecture, the MC9S12A256BCFU does not include dual CAN - a distinction confirmed in derivative comparison tables within the official Device User Guide.

What is the ADC resolution and channel count on the MC9S12A256BCFU?

The MC9S12A256BCFU contains two independent 10-bit Analog-to-Digital Converters: ATD0 with 8 input channels and ATD1 with 16 input channels. Both support hardware-triggered conversions, configurable sample times, and scan sequencing - enabling precise, synchronized sensor acquisition in applications such as throttle position sensing and battery voltage monitoring on the MC9S12A256BCFU.

Is the MC9S12A256BCFU pin-compatible with the MC9S12DP256B?

No, the MC9S12A256BCFU is not pin-compatible with the MC9S12DP256B. Although both share the 112-pin LQFP package and many peripheral functions, their pin assignments differ - particularly for CAN, SPI, and I/O multiplexing. The Device User Guide explicitly lists them as separate derivatives in Table 0-1, confirming distinct signal mappings and requiring unique PCB layouts for each part, including the MC9S12A256BCFU.