High-precision mode increases the accuracy of the data measurement by accumulating ADC conversion results. This accumulation is useful for applications where the level of precision required to accurately measure the sensor output must be higher than 12 bits.

For this mode, set the OPMODE_SEL register to 111b. In this mode, the ADC starts converting and starts accumulating the conversion results in an accumulator when the SEQ_START bit is set. The ADC stops accumulating after 16 conversion results. The accumulator contains one 16-bit conversion result. The ADC has an accumulator for each analog input channel. If the operation of the ADC is aborted in high-precision mode before the BUSY/RDY pin goes low because the SEQ_ABORT bit is set by the user, the ADC provides invalid data and the internal data buffer (Figure 7-8), provides zeroes as output. In this mode, the BUSY/RDY can wake up the MCU or host from sleep or hibernation when accumulation completes. The steps for configuring the ADC into high-precision mode are illustrated in Figure 7-23.

A. For setting the operation mode to high-precision mode, see Figure 7-11.

B. Select the channels in the AUTO_SEQ_CHEN register.

C. Select the oscillator by configuring the OSC_SEL register and configure the NCLK_SEL register.

D. Enable the accumulator by setting the bits in the ACC_EN register.

E. Set the SEQ_START bit in the START_SEQUENCE register.

F. Read the ACC_CHx_xxx registers.

G. Select another operation mode in the OPMODE_SEL register.

H. For reading and writing registers, see the Section 7.5 section.

Figure 7-23 Configuring ADC in High-Precision Mode

Abort the current sequence by setting the SEQ_ABORT bit before changing the ADC operation mode or ADC configuration.

Figure 7-24 and Figure 7-25 show the accumulation of conversion results in high-precision mode.

Figure 7-24 High-Precision Mode With Single-Channel Configurations

Figure 7-25 High-Precision Mode With Dual-Channel Configurations