1 Device is Not Functional

This section provides a list of questions that can be raised if the part is not functional. It is recommended to check every entry of the list and measure the requested parameters. If the issue cannot be solved, check the next section or contact the technical support team.

Is the power supply enabled?
Is the board connected to the power supply?
Are the correct jumpers set on the board?
Is the connected voltage in the specified range?
- What is the voltage and is it stable?
  If the measured voltage is not in the specified or expected range, it is an indication that the hardware or the power supply has an issue. A voltage that is too low can lead to the part not working, while an overvoltage can damage the part. It is recommended that the voltage that is connected be measured with calibrated equipment prior to its connection to the device.
- Is a suitable buffering capacitor of the power supply used?
Is the current limitation on the power supply set to a value that is too low?
Is the current consumption in the expected range?
- What is the current consumption of the device?
  An unexpected high current could be caused by damage of the part or by many other factors, like floating pins, wrong connection or by an incorrect measurement.
Is a change of NPRWON pins visible during or after wake event?
- Which pin shows the change, and what is the new level?
  The NPWRON pins (PC1, PC2, PC3, PC4, PC5 and PB7) are controlled from hardware during the OFF mode. After the wake event, the device will be initialized and the configuration from the EEPROM will be loaded to the I/O register. Depending on the configuration from the EEPROM, it is possible to see a change from high to low or vice versa during the system start-up.
Is the NRESET pin set to the right value (high)?
- What is the value and is it stable?
  If the NREST pin is not set to the correct level, the part will hold in the Reset state with no reaction on communication requests.
Is DVCC present after wake up?
- What is the voltage level prior to and after the wake event?
  DVCC is OFF prior the wake event. After the wake is triggered, the typical value is 1.35V after ~100 µs. A slight deviation (higher) from that value could be an indication that it is stuck in reset or any other issue. Therefore, it is recommended to measure this value with the highest possible accuracy.
How are the fuses set?
With one of the fuses (BOOTRST), customers can select if the device starts after power-up of the ROM firmware or a software stored in FLASH memory. Therefore, it is necessary to know what the fuse setting is. Details on the fuses can be taken from the subsequent sections or from the data sheet of the product.
Was an ABA test performed? If not, it is recommended to do it.
An ABA test could give a hint about the source of the issue. If the issue is following the device, it is an indication of a problem from Microchip. It is recommended to also use a second device known as a good unit to verify if it is a general issue or a single occurrence issue.
What is configured in the EEPROM memory?
It might be possible that a wrong mode is selected in the EEPROM configuration. If that happens, it might be possible that the part is not reacting as expected. An example would be the pureRXMode from the ATA578x product family. If this mode is chosen, it is possible that the part is not reacting on any external request.