Method and apparatus for determining status element total with sequentially coupled counting status circuits

An operation method of a fail bit count, comprising:

• processing a plurality of status circuits in a sequential order to determine a count of bits having one of pass and fail status;
• storing an initial count status in response to said one of pass and fail status in an upper latch in status circuits of the plurality of status circuits, the upper latch including a first end and a second end;
• indicating, with a pass gate in of the plurality of status circuits including two switches having control gates connected to the first end and the second end respectively of the upper latch, whether the initial count status has been counted in the plurality of status circuits;
• and
• on condition that the initial count status stored in the upper latch corresponds to the fail status, flipping the initial count status using a lower latch which is electrically coupled to an input of the status circuit to receive an output from a previous status circuit in the sequential order.