4.6 Enhanced Resolution Mode
To improve the stability of the temperature readings, it is recommended to average successive conversions of the VBG and VTEMP voltages. For this purpose, the ADC controller features an Enhanced Resolution mode. Refer to “Enhanced Resolution Mode” and “Digital Averaging Function” in the “Analog-to-Digital Converter (ADC) Controller” section of the SAMA7D6 Series data sheet for a detailed description.
- Set ADC_EMR.OSR to the required value. The higher the OSR value, the greater the stability of the temperature reading and the longer the acquisition time. Setting ADC_EMR to a non-zero value changes the raw 12-bit output data to 13-, 14-, 15-, or 16-bit data.
- The following table shows the correspondence between the temperature reading stability and the acquisition time. The temperature reading stability is measured as the standard deviation of a large set of samples.
- Set ADC_EMR.ASTE to perform all required conversions with a single trigger.
|
ADC_EMR.OSR |
ADC Output Data Format |
TJ Reading Stability (Standard Deviation) |
VTEMP or VBG Acquisition Time |
|---|---|---|---|
| 0 (NO_AVERAGE) | 12-bit | 0.53°C | 2 µs |
| 1 (OSR4) | 13-bit | 0.25°C | 8 µs |
| 2 (OSR16) | 14-bit | 0.14°C | 32 µs |
| 3 (OSR64) | 15-bit | 0.08°C | 128 µs |
| 4 (OSR256) | 16-bit | 0.05°C | 0.5 ms |