We are facing a false key detection on our product. We are using the Keypad Decoder ADP5585 IC for the KEypad logic on our product.
The datasheet of ADP5585 specifies that a Key press will be detected after a key scan during which the columns will go high and there will be a minimum of two cycles of polling.
The same behavior is observed on the corresponding column line when a key is pressed manually as shown in the figure below.
In this figure, we can clearly see that the column goes high followed by key scan.
Whereas, during a false key detection, we do not see a key scan on the column line(as shown below).
But still, the FIFO records key press and key release even without a key scan occurring on that particular column line(as shown below).
How does the FIFO value get updated without a KEyscan??