MC9S12A128CFUE datasheet by Freescale Semiconductor

MC9S12A128CFUE Frequently Asked Questions (FAQs)

• What is the maximum clock frequency of the MC9S12A128CFUE?
  The maximum clock frequency of the MC9S12A128CFUE is 25 MHz.
• How do I configure the internal oscillator on the MC9S12A128CFUE?
  The internal oscillator on the MC9S12A128CFUE can be configured using the OSCCTL register. The oscillator frequency can be set to 4 MHz, 8 MHz, or 16 MHz by writing the appropriate values to the FOSCSEL bits in the OSCCTL register.
• What is the purpose of the COP (Computer Operating Properly) timer on the MC9S12A128CFUE?
  The COP timer is a watchdog timer that resets the microcontroller if it does not receive a 'kick' signal within a specified time period. This is used to prevent the microcontroller from getting stuck in an infinite loop or other abnormal operation.
• How do I use the SCI (Serial Communication Interface) module on the MC9S12A128CFUE?
  The SCI module on the MC9S12A128CFUE is used for asynchronous serial communication. To use it, configure the SCI control register (SCICR) to set the baud rate, data bits, and stop bits. Then, use the SCI data register (SCIDR) to transmit and receive data.
• What is the purpose of the PLL (Phase-Locked Loop) on the MC9S12A128CFUE?
  The PLL on the MC9S12A128CFUE is used to multiply the clock frequency of the internal oscillator to generate a higher frequency clock signal. This allows the microcontroller to operate at a higher frequency than the internal oscillator frequency.