MC9S12DJ64CFUE datasheet by Freescale Semiconductor

MC9S12DJ64CFUE Frequently Asked Questions (FAQs)

• What is the maximum clock frequency that can be used with the internal oscillator?
  The maximum clock frequency that can be used with the internal oscillator is 25 MHz, but it's recommended to use a crystal oscillator for frequencies above 20 MHz for better stability and accuracy.
• How do I configure the chip select signals for the external memory interface?
  The chip select signals can be configured using the MEMCTL register. The MEMCTL register allows you to select the memory type, memory width, and chip select polarity. Refer to the datasheet for the specific bit settings for your application.
• What is the maximum current that can be sourced or sunk by the GPIO pins?
  The maximum current that can be sourced or sunk by the GPIO pins is 25 mA. However, it's recommended to limit the current to 10 mA or less to ensure reliable operation and to prevent overheating.
• How do I implement a watchdog timer reset?
  To implement a watchdog timer reset, you need to configure the COP (Computer Operating Properly) module. The COP module generates a reset signal if the watchdog timer is not serviced within a specified time period. Refer to the datasheet for the specific register settings and timing requirements.
• What is the purpose of the VREG pin, and how do I use it?
  The VREG pin is used to regulate the internal voltage regulator. It's recommended to connect a 10 uF capacitor between the VREG pin and ground to ensure stable operation. The internal voltage regulator can be enabled or disabled using the SYNRG register.