SLVSCO4D July 2015 – February 2019 TPS65917-Q1
The user can enable periodic conversions to compare one or two channels with a predefined threshold level. One or two channels can be selected by programming the GPADC_AUTO_SELECT register. The thresholds and polarity of the conversion can be programmable through the
GPADC_THRES_CONV0_LSB, GPADC_THRES_CONV0_MSB, GPADC_THRES_CONV1_LSB, and GPADC_THRES_CONV1_MSB registers. In addition, software must select the conversion interval with the GPADC_AUTO_CTRL register and enable the periodic conversion with the AUTO_CONV0_EN and AUTO_CONV1_EN bits.
The GPADC does not need to be enabled separately. The control logic enables and disables the GPADC automatically to save power. The latest conversion result is always stored in the GPADC_AUTO_CONV0_LSB, GPADC_AUTO_CONV0_MSB, GPADC_AUTO_CONV1_LSB, and GPADC_AUTO_CONV1_MSB registers. All selected channels are queued and converted from channel 0 to 7. The first (lower) converted channel result is placed in the GPADC_AUTO_CONV0 register and the second result is placed in the GPADC_AUTO_CONV1 register. Therefore, it is recommended to place the lower channel for conversion in the AUTO_CONV0_SEL bit field of the GPADC_AUTO_SELECT register, and the higher channel for conversion in the AUTO_CONV1_SEL bit field.
If the conversion result triggers the threshold level, an INT interrupt is generated and the conversion result is stored. If the interrupt is not cleared or the results are not read before another auto-conversion is complete, then the registers store only the latest results, discarding the previous ones. The auto-conversion is never stopped by an uncleared interrupt or unread registers.
Programming the triggering of the threshold level can also generate shutdown. This programming is available independently for the CONV0 and CONV1 channels and is enabled by setting the SHUTDOWN bits in the GPADC_AUTO_CTRL register. During sleep and off modes, only channels 0 to 4 can be converted. For channels 5 and 6, conversion is possible in sleep state if the thermal sensor is not disabled.