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 of an ADC start of conversion issued by software through the SC bit,
software has to wait for at least 9 SOC CLK 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.