Some embodiments relate to an imaging system including an active pixel a comparator, a write control circuit, and an analog-to-digital conversion (ADC) memory. The active pixel may include a photodiode and a plurality of transistors. The comparator may be operative coupled to the active pixel and configured to receive an output of the active pixel. The write control circuit may be operative coupled to the comparator and configured to receive an output from the comparator. The ADC memory may be operatively coupled to the write control circuit. A data structure may be stored in the ADC memory, and may be configured to store at least a first data string, which may include a set of flag bits for identifying each ADC operation performed and a set of ADC data bits.