CAPACITIVE SENSING WITH PROGRAMMABLE LOGIC FOR TOUCH SENSE ARRAYS

• US 20120268416A1
• Filed: 09/28/2011
• Published: 10/25/2012
• Est. Priority Date: 04/19/2011
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Pirogov, Oleksandr, Kremin, Viktor, Konovalov, Anton, Mohammed, Haneef, Ogirko, Roman, Yarosh, Andriy, Sharamaga, Roman, Maharyta, Andriy
• Granted Patent: US 8,681,122 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch sense controller configured to be coupled to a touch sense array is disclosed. The touch sense controller includes programmable logic that includes programmable logic elements configured to manage measurement of capacitance associated with the touch sense array.

Claims

1. A circuit, comprising

a touch sense controller configured to be coupled to a touch sense array, wherein the touch sense controller comprises:

programmable logic comprising a plurality of programmable logic elements configured to manage measurement of capacitance associated with the touch sense array.

2. The circuit of claim 1, wherein the plurality of programmable logic elements comprises a plurality of universal digital logic blocks (UDB) of the touch sense controller.

3. The circuit of claim 1, wherein the programmable logic is configured as a programmable sequencer that is a hardware-controlled scanning thread to scan the touch sense array without interaction of a processing core of the touch sense controller.

4. The circuit of claim 3, wherein the programmable sequencer comprises a run-time reconfigurable state machine.

5. The circuit of claim 1, wherein the programmable logic is configured to apply TX signals on TX pins and receive RX signals on RX pins without interaction of the processing core.

6. The circuit of claim 5, wherein the programmable logic is configured to notify the CPU when a full panel scan is completed via an interrupt.

7. The circuit of claim 5, wherein the programmable logic is configured to begin a full panel scan in response to a start-of-scan signal received from the processing core.

8. The circuit of claim 1, wherein the programmable logic is reconfigurable during system boot time according to properties of the touch sense array.

9. The circuit of claim 1, wherein the programmable logic is configured to perform an adaptive scanning algorithm.

10. The circuit of claim 1, wherein the plurality of programmable logic elements comprises an RX slots control sequencer block configured to selectively enable or disable RX measurement channels to take part in a conversion.

11. The circuit of claim 1, wherein the plurality of programmable logic elements comprises a TX pins control sequencer block configured to apply TX excitation signals to TX pins.

12. The circuit of claim 11, wherein the TX pins control sequencer block is configured to apply one of single-TX and multiphase-TX excitation signals having a programmable phase pattern and common TX signal state.

13. The circuit of claim 1, wherein the plurality of programmable logic elements comprises an analog-to-digital converter control sequencer block configured to measure a value proportional to a mutual capacitance created by a TX-RX intersection.

14. An apparatus, comprising:

a processing device configured to detect a conductive object proximate to a touch sense array, wherein the processing device comprises;

a processing core; and

programmable logic coupled to the processing core, the programmable logic comprising a plurality of programmable logic elements configured to manage measurement of capacitance associated with the touch sense array.

15. The apparatus of claim 14, wherein the plurality of programmable logic elements comprises a plurality of universal digital logic blocks (UDB) of the processing device.

16. The apparatus of claim 14, wherein the programmable logic is configured as a programmable sequencer that is a hardware-controlled scanning thread to scan the touch sense array without interaction of the processing core of the processing device.

17. The apparatus of claim 16, wherein the programmable sequencer comprises a run-time reconfigurable state machine.

18. The apparatus of claim 16, wherein the programmable sequencer is configured to apply TX signals on TX pins and receive RX signals on RX pins without interaction of the processing core.

19. A method, comprising:

programming programmable logic comprising a plurality of programmable logic elements configured to manage measurement of capacitance associated with the touch sense array.

20. The method of claim 19, further comprising:

reconfiguring or reprogramming the programmable logic during system boot time or system run time according to properties of the touch sense array.