29.4.5 Calibration Bits

Calibration bits do not interfere with the embedded Flash memory plane.

The calibration bits cannot be modified.

The status of calibration bits is returned by the SEFC. The sequence is the following:

  1. Execute the ‘Get CALIB Bit’ command by writing EEFC_FCR.FCMD with the GCALB command. Field EEFC_FCR.FARG is meaningless.
  2. Calibration bits can be read by the software application in EEFC_FRR. The first word read corresponds to the first 32 calibration bits. The following reads provide the next 32 calibration bits as long as it is meaningful. Extra reads to EEFC_FRR return 0.

The 12-MHz internal RC oscillator is calibrated in production. This calibration can be read through the GCALB command. The following table shows the bit implementation.

Table 29-4. Calibration Bit Indexes
DescriptionEEFC_FRR Bits
12-MHz RC calibration output[38-32]