3.11 Save

The Save function allows users to preserve their configurations in the device's non-volatile memory. The target is to have the complete device configuration ready for all coming start-ups w/o the necessity to rewrite the configuration by the host.

Initialize

Write 1 to DEVCTRL.SAVE to save the configuration. Promptly, this bit will reset to 0.

In this scenario, the DEVCTRL.RESET value will not be considered during the save operation.

Operation

Save Configuration

This device features integrated None Volatile Memory NVM for storing the device configuration. Out of the box, the device is pre-configured with factory settings. However, users are encouraged to modify and overwrite these settings, with the changes preserved in the NVM. Starting from the next power-up, the MTCH2120 will execute according to these settings - no need for the host to rewrite the setting at every startup via the I2C bus. Each time a save operation is initiated, the system will calculate a 16bit-CRC for the configuration to verify its integrity and prevent corruption.

If the DEVSTA.SAVE bit reads as 1, it signifies a failure in the save operation (for additional information, refer to the Device Status section). It is imperative for users to check this bit after executing each save command. The bit will reset only on a successful save or when the device performs a reset.
Note:
  1. The FREQ[n] and THRESHOLD[n] register values will be reset to previously stored values when the Autotune and Easytune functions are enabled. Refer to the Autotune and Easytune sections for more information.
  2. After issuing a Save command, the host application can monitor the CRC register to understand whether the CRC computed by the host matches to confirm a successful save operation. The host can use this CRC value later to see whether the device operates at the required configuration.

Load Configuration

Configurations will be retrieved from the NVM for every device reset. These configurations undergo a validation process using a computed 16bit-CRC to ensure their integrity. If the loaded configuration is corrupted, the device will revert to the manufacturer's default configuration settings, and the default configurations will be stored in the NVM.

It is important to note that if the DEVSTA.LOAD bit is read as 1, signifying a failure in the load operation. Users must check this bit that follows every device reset. The bit will be reset to 0 only after a successful load operation.