S12XA Automotive and Industrial Microcontrollers (MCUs)

Block Diagram

S12XA Microcontroller Block Diagram

S12XA Microcontroller Block Diagram


HCS12X Core

  • 16-bit HCS12X CPU
    • Upward compatible with HCS12 instruction set
    • Interrupt stacking and programmer's model identical to HCS12
    • Instruction queue
    • Enhanced indexed addressing
    • Enhanced instruction set
  • EBI (external bus interface)
  • MMC (module mapping control)
  • INT (interrupt controller)
  • DBG (debug module to monitor HCS12X CPU and XGATE bus activity)
  • BDM (background debug mode)


  • Peripheral co-processor
  • Parallel processing module offloads the CPU by providing high-speed data processing transfer between peripheral modules, RAM and I/O ports
  • Data transfer between flash EEPROM, peripheral modules and I/O ports

PIT (periodic interrupt timer)

  • Four timers with independent time-out periods
  • Time-out periods selectable between 1 and 224 bus clock cycles


  • Low noise/low power Pierce oscillator
  • Phase-lock look (PLL)
  • COP watchdog
  • Real-time interrupt
  • Clock monitor
  • Fast wake-up from stop mode

Part numbers include: MC9S12XA256CAA, MC9S12XA256CAG, MC9S12XA256CAL, MC9S12XA256VAA, MC9S12XA256VAL, MC9S12XA512CAA, MC9S12XA512CAG, MC9S12XA512CAL, MC9S12XA512VAA.


Quick reference to our documentation types.

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Quick reference to our board types.

5 hardware offerings


Quick reference to our software types.

5 software files

Note: For better experience, software downloads are recommended on desktop.

Engineering Services

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