The ADC status register, STA, contains two bits—ASCACT and BUSY.
- BUSY equaling ‘1’ indicates that the ADC is busy performing a sample or conversion operation.
- For single channel single conversion, BUSY signals that a trigger has been received and sample or conversion is ongoing. BUSY is cleared when the conversion completes.
- For repeat single conversion, BUSY signals that repeat single operation has begun and has not ended. BUSY is cleared when ENC is written ‘0’ and the last conversion completes.
- For sequence of channels conversion, BUSY signals that the sequence of channels conversion has started. BUSY is cleared at the end of the sequence
- For repeat sequence of channels conversion, BUSY signals the repeat sequence is ongoing. BUSY is cleared when ENC is written ‘0’ and the last conversion in the sequence completes.
Note: In case an ADC start of conversion is issued by the software through the SC bit, the software must wait for at least nine CLKSVT clock cycles if polling for the BUSY status bit in the program code. This is to account for internal clock synchronization latencies before the ADC status bit is updated.