Frequency shifting for simultaneous active matrix display update and in-cell capacitive touch

A processing system, comprising:

• a display module configured to drive a display signal onto at least one of a plurality of display electrodes for updating a display;
• and
• a sensing module configured to:
• drive a first capacitive sensing signal having a first frequency onto at least one of the plurality of sensor electrodes, wherein the first frequency is synchronized to the display signal,
• drive a second capacitive sensing signal having a second frequency onto the at least one sensor electrode, wherein the first and second frequencies differ and a timing of the display signal is adjusted to maintain synchronization with the second frequency,
• wherein the capacitive sensing signal and the display signal are driven in parallel for at least some period of time.

A method, comprising:

• driving a display signal onto at least one of a plurality of display electrodes for updating a display,
• driving a first capacitive sensing signal having a first frequency onto at least one of a plurality of sensor electrodes, wherein the first frequency is synchronized to the display signal, and
• driving a second capacitive sensing signal having a second frequency onto the at least one sensor electrode, wherein the first and second frequencies differ and a timing of the display signal is adjusted to maintain synchronization with the second frequency,
• wherein each capacitive sensing signal and the display signal are driven in parallel for at least some period of time.