51.6.15 Automatic Error Correction

The AFEC features automatic error correction of conversion results. Offset and gain error corrections are available. The correction can be enabled for each channel and correction values (offset and gain) are defined per Sample & Hold unit.

To enable error correction, the ECORR bit must be set in the AFEC Channel Error Correction register (AFEC_CECR). The offset and gain values used to compensate the results are set per Sample & Hold unit basis using the AFEC Correction Select register (AFEC_COSR) and the AFEC Correction Values register (AFEC_CVR). AFEC_COSR is used to select the Sample & Hold unit to be displayed in AFEC_CVR. This selection applies both to read and write operations in AFEC_CVR.

AFEC_CVR.OFFSETCORR and AFEC_CVR.GAINCORR must be filled with the values of corrective data. This data is computed from two measurement points in signed format. The correction is the same for all functional modes.

The final conversion result after error correction is obtained using the following formula, which is implemented after averaging in 2’s complement format, with:
  • OFFSETCORR—the offset correction value. OFFSETCORR is a signed value.
  • GAINCORR—the gain correction value

  • Gs—the value 15

Corrected Data = Converted Data + OFFSETCORR × GAINCORR 2 Gs
Figure 51-14. AFE Digital Signal Processing