Large PCAP screen with multiple touch controller ASICs with interleaved connections

1. A projected capacitive (PCAP) touch system comprising:

a touchscreen; and

a first and a second touch controller application-specific integrated circuit (ASIC) communicatively coupled to the touchscreen to detect self-capacitive touch data from touchscreen electrodes over an entire touch area of the touchscreen, wherein a first driver circuit of the first touch controller ASIC comprises first connections to a first subset of the touchscreen electrodes, wherein a second driver circuit of the second touch controller ASIC comprises second connections to a second subset of the touchscreen electrodes, wherein the first subset of the touchscreen electrodes is interleaved with the second subset of the touchscreen electrodes.

2. The PCAP touch system of claim 1 , wherein the first and the second touch controller ASICs do not exchange raw self-capacitance data during a measurement frame.

3. The PCAP touch system of claim 1 , wherein the first and the second touch controller ASICs generate coarse X and Y self-capacitance data over the entire touch area of the touchscreen.

4. The PCAP touch system of claim 1 , further comprising one or more processors coupled to the first and the second touch controller ASICs, wherein the one or more processors are configured to: determine a final touch coordinate based on coarse touch coordinate data from the first and the second touch controller ASICs.

5. The PCAP touch system of claim 4 , wherein the first subset of the touchscreen electrodes is odd numbered and the second subset of touchscreen electrodes is even numbered.

6. The PCAP touch system of claim 4 , wherein first coarse touch coordinate data from the first touch controller ASIC of the coarse touch coordinate data, is based on a pitch size of the touchscreen and a sum of a number of the first and the second touch controller ASICs.

7. The PCAP touch system of claim 4 , wherein the first touch controller ASIC is configured to calculate first coarse touch coordinate data comprising: a partial sum of mutual capacitance measurements satisfying a significant touch threshold across a third subset of touchscreen electrodes of the touchscreen; an X touch coordinate associated with the third subset of touchscreen electrodes; and a Y touch coordinate associated with the third subset of touchscreen electrodes, wherein the partial sum, the X touch coordinate, and the Y touch coordinate are calculated by the first touch controller ASIC without communicating with the second touch controller ASIC.

8. The PCAP touch system of claim 7 , wherein third connections between the first touch controller ASIC and the third subset of touchscreen electrodes of the touchscreen, are interleaved with fourth connections, wherein the fourth connections are between the second touch controller ASIC and a fourth subset of touchscreen electrodes of the touchscreen.

9. The PCAP touch system of claim 8 , wherein first coarse touch coordinate data from the first touch controller ASIC of the coarse touch coordinate data, is based at least on a number of horizontal and vertical electrode intersections of the third subset of the touchscreen electrodes whose mutual capacitance measurements satisfy the significant touch threshold.

10. The PCAP touch system of claim 9 , wherein the mutual capacitance measurements are delayed until after self-capacitance measurements are made.

11. The PCAP touch system of claim 9 , wherein self-capacitance measurements are delayed until after the mutual capacitance measurements are made.

12. A method, for a first touch controller application-specific integrated circuit (ASIC), comprising:

determining a first subset of coarse touch coordinate data received from first driver circuits coupled to a first subset of touchscreen electrodes of a projected capacitive (PCAP) touchscreen, wherein the first subset of touchscreen electrodes is interleaved with a second subset of touchscreen electrodes, wherein the second subset of touchscreen electrodes is coupled to second driver circuits of a second touch controller ASIC, and wherein the first subset of touchscreen electrodes and the second subset of touchscreen electrodes together cover an entire touch area of the PCAP touchscreen; and

transmitting the first subset of coarse touch coordinate data to a processor, wherein the processor receives a second subset of coarse touch coordinate data from the second touch controller ASIC, and wherein the processor determines final touch coordinates based on the first subset of coarse touch coordinate data and the second subset of coarse touch coordinate data.

13. The method of claim 12 , wherein the first and the second touch controller ASICs do not exchange raw mutual capacitance or self-capacitance data during a measurement frame.

14. The method of claim 12 , wherein the first subset of coarse touch coordinate data comprises coarse X and Y self-capacitance data.

15. The method of claim 12 , wherein a coarse pitch size of the first subset of coarse touch coordinate data from the first touch controller ASIC is based on a pitch size of the PCAP touchscreen and a sum of a number of the first and the second touch controller ASICs.

16. The method of claim 12 , wherein the first subset of touchscreen electrodes of the PCAP touchscreen is odd numbered and the second subset of touchscreen electrodes is even numbered.

17. The method of claim 12 , wherein the first subset of coarse touch coordinate data comprises:

a partial sum of mutual capacitance measurements satisfying a significant touch threshold across a third subset of touchscreen electrodes of the PCAP touchscreen; an X touch coordinate associated with the third subset of touchscreen electrodes; and a Y touch coordinate associated with the third subset of touchscreen electrodes, and

wherein the determining a first subset of coarse touch coordinate data is performed without communicating with the second touch controller ASIC.

18. The method of claim 17 , wherein first connections between the first touch controller ASIC and a third subset of touchscreen electrodes of the PCAP touchscreen, are interleaved with second connections, wherein the second connections are between the second touch controller ASIC and a fourth subset of touchscreen electrodes of the PCAP touchscreen.

19. The method of claim 18 , wherein the first subset of touchscreen electrodes is substantially perpendicular to the third subset of touchscreen electrodes.

20. A non-transitory computer readable medium having stored therein one or more instructions that, when executed by one or more processors, cause the one or more processors of a first touch controller application-specific integrated circuit (ASIC) to perform operations, the operations comprising:

determining a first subset of coarse touch coordinate data received from first driver circuits coupled to a first subset of touchscreen electrodes of a projected capacitive (PCAP) touchscreen, wherein the first subset of touchscreen electrodes is interleaved with a second subset of touchscreen electrodes, wherein the second subset of touchscreen electrodes is coupled to second driver circuits of a second touch controller ASIC, wherein the first subset of touchscreen electrodes and the second subset of touchscreen electrodes together cover an entire touch area of the PCAP touchscreen; and

transmitting the first subset of coarse touch coordinate data to a processor, wherein the processor receives a second subset of coarse touch coordinate data from the second touch controller ASIC, and wherein the processor determines final touch coordinates based on the first subset of coarse touch coordinate data and the second subset of coarse touch coordinate data.