Calibration can be done by measuring the output of the FlashTemp user module at two extreme temperatures and then interpolating between these two readings. This can give an accuracy of about ±3 °C. To get better temperature measurement accuracy you can use a high-resolution ADC placed in ASC21 block instead of the FlashTemp user module. Connect VT to the input of ADC. Connect the B input of ADC conversion block to the VLOW by manually modifying control register, as temperature sensor requries differential sensing. Later, you can read the ADC for 2 extreme temperatures (i.e. -40°C and +85°C) and make linear interpolation between two points.