Touch sensing

A touch detection system, comprising:

• a touch sensor array comprising unit cells;
• a transmit sequencer configured to generate an excitation signal;
• an analog-to-digital-converter unit configured to measure responses of the unit cells to the excitation signal;
• and
• a processing unit configured to:
• generate a first capacitance map based on the responses;
• filter the first capacitance map, by rows, in a first band pass filter to generate a second capacitance map, wherein the filtering of the first capacitance map is by:
• storing a first row of the first capacitance map in a memory block,
• selecting a window of data elements in the memory block,
• generating a filter output for the window, and
• sliding the window through the memory block and iterating the generating of the filter output;
• and
• detect a touch event based on the second capacitance map.

A touch detection system, comprising:

• a display comprising a touch sensor array having transmit lines and receive lines;
• a transmit sequencer configured to generate excitation signals, by transmit line, on the touch sensor array;
• an analog-to-digital-converter unit configured to measure responses of the receive lines to the excitation signals;
• and
• a processing unit configured to:
• generate a first capacitance map based on the responses;
• filter the first capacitance map, by rows, in a first band pass filter to generate a second capacitance map, wherein the filtering of the first capacitance map is by:
• storing a first row of the first capacitance map in a memory block,
• selecting a window of data elements in the memory block,
• generating a filter output for the window, and
• sliding the window through the memory block and iterating the generating of the filter output;
• and
• detect a touch event based on the second capacitance map.