Semiconductor device and electronic device

1. A semiconductor device which is formed on one semiconductor substrate of single-crystal silicon, comprising:

a touch panel controller operable to perform pulse-drive control on a first group of electrodes of a touch panel and detection control of touch signals arising on a second group of electrodes capacitively coupled with the first group of electrodes;

a processor operable to perform control of the touch panel controller; and

a display driver operable to perform drive control of a display panel,

wherein the display driver operates while the processor remains in a sleep state,

wherein the touch panel controller does not operate while the processor remains in the sleep state,

wherein the sleep state is set by execution of a sleep command by the processor and is cancelled in response to an interrupt sent to the processor,

wherein the processor returns to a workable state from the sleep state each time a given length of time elapses, and causes the touch panel controller to perform an action of detecting a touch/no touch,

wherein when the processor cannot acquire a result of judgment as “being touched”, the processor returns to the sleep state again, and waits for a given length of time to elapse,

wherein the processor returns to its workable state from the sleep state each time the given length of time elapses,

wherein upon receipt of the result of judgment as “being touched”, the processor takes an action to a host processor disposed outside of the semiconductor device for processing the result, and waits for a touch-scan-activation instruction in response to the action taken by the processor from the host processor disposed outside of the semiconductor device for causing the touch panel controller to perform an action of detecting a touch/no touch, and the display driver waits for an activation instruction in response to the action taken by the processor from the host processor disposed outside of the semiconductor device, and

wherein the display driver receives the activation instruction from the host processor disposed outside of the semiconductor device before the touch panel controller receives the scan-activation instruction from the host processor disposed outside of the semiconductor device.

2. The semiconductor device according to claim 1 , wherein a touch condition when the processor judges as “being touched” is that more than one touch position can be detected.

3. The semiconductor device according to claim 2 ,

wherein the touch-scan-activation instruction is formed based on a time-out interruption by a timer counter in the processor,

wherein the touch-scan-activation instruction includes an instruction for starting touch scan at intervals shorter than the given length of time, and

wherein upon receipt of the touch-scan-activation instruction, the processor performs a coordinate calculation of a touch position based on touch detection signals obtained by the touch panel.

4. The semiconductor device according to claim 1 , wherein the touch panel controller has:

a plurality of drive terminals connected with the first group of electrodes of the touch panel;

a first drive circuit operable to output a drive pulse from the drive terminals;

a plurality of detection terminals connected with the second group of electrodes of the touch panel;

a second drive circuit operable to output a drive pulse to the detection terminals;

a detection circuit operable to accumulate signals input, more than once, through the detection terminals in synchronization with a change in the drive pulse thereby creating detection data; and

a timing control circuit operable to control a touch-detecting action by use of the first and second drive circuits and the detection circuit, and

wherein the timing control circuit has

a first touch detection mode in which detection data are created by accumulating, by use of the detection circuit, signals input more than once from the detection terminals in synchronization with a change of the drive pulse output by the first drive circuit, and

a second touch detection mode in which detection data are created by accumulating, by use of the detection circuit, signals input more than once from the detection terminals of one of groups consisting of the even and odd detection terminals respectively in synchronization with a change of the drive pulse output from the second drive circuit through the detection terminals of the other group.

5. The semiconductor device according to claim 4 ,

wherein the action of detecting a touch/no touch which the processor returns to its workable state from the sleep state to cause the touch panel controller to perform each time a given length of time elapses is an action according to the second touch detection mode.

6. The semiconductor device according to claim 5 ,

wherein the processor in the sleep state returns to its workable state from the sleep state each time the given length of time elapses,

wherein, when acquiring the result of judgment as “being touched”, the processor makes a request for an interrupt to an outside of the semiconductor device, and waits for a touch-scan-activation instruction from the touch panel controller, and the display driver waits for an activation instruction, and

wherein the touch-detecting action in response to the touch-scan-activation instruction is an action according to the first touch detection mode.

7. The semiconductor device according to claim 6 , wherein a touch condition when the processor judges as “being touched” in the second touch detection mode is that more than one touch position can be detected.

8. The semiconductor device according to claim 7 ,

wherein the touch-scan-activation instruction includes an instruction for starting touch scan at intervals shorter than the given length of time, and

wherein upon receipt of the touch-scan-activation instruction, the processor performs a coordinate calculation of a touch position based on touch detection signals obtained by the touch panel.

9. The semiconductor device according to claim 4 , wherein the timing control circuit has a mode register capable of rewritably storing instruction data for providing an instruction on which of the first and second touch detection modes to select.

10. The semiconductor device according to claim 4 , wherein the timing control circuit has a mode register capable of rewritably storing instruction data for providing an instruction on which group of the even and odd detection terminal groups to direct the drive pulse to, and on which group to accept detection signal input from.

11. The semiconductor device according to claim 4 , wherein the second drive circuit includes:

a voltage-select switch circuit operable to alternately select voltages having different levels; and

a buffer amplifier operable to output, to the corresponding detection terminal, voltages output by the voltage-select switch circuit.

12. An electronic device comprising:

a host processor;

a touch panel having a plurality of drive electrodes, a plurality of detection electrodes, and capacitance components formed between each of the pluralities of electrodes;

a touch panel controller operable to perform pulse-drive control on a first group of electrodes of the touch panel and detection control of touch signals arising on a second group of electrodes capacitively coupled with the first group of electrodes;

a processor connected with the host processor and operable to control the touch panel controller;

a display panel; and

a display driver connected with the host processor and operable to perform drive control of the display panel,

wherein the touch panel controller, the processor, and the display driver are formed on one semiconductor substrate of single-crystal silicon,

wherein the display driver operates while the processor remains in a sleep state,

wherein the touch panel controller does not operate while the processor remains in the sleep state,

wherein the sleep state is set by execution of a sleep command by the processor and is cancelled in response to an interrupt sent to the processor,

wherein the processor returns to a workable state from the sleep state each time a given length of time elapses, and causes the touch panel controller to perform an action of detecting a touch/no touch,

wherein, when the processor cannot acquire the result of judgment as “being touched”, the processor returns to the sleep state again, and waits for the given length of time to elapse,

wherein the processor in the sleep state returns to its workable state from the sleep state each time the given length of time elapses,

wherein upon receipt of the result of judgment as “being touched”, the processor takes an action to the host processor for processing the result, and waits for a touch-scan-activation instruction in response to the action taken by the processor from the host processor for causing the touch panel controller to perform an action of detecting a touch/no touch, and the display driver waits for an activation instruction in response to the action taken by the processor from the host processor, and

wherein the display driver receives the activation instruction from the host processor before the touch panel controller receives the scan-activation instruction from the host processor.

13. The electronic device according to claim 12 , wherein a touch condition when the processor judges as “being touched” is that more than one touch position can be detected.

14. The electronic device according to claim 13 ,

wherein the touch-scan-activation instruction is formed based on a time-out interruption by a timer counter in the processor,

wherein the touch-scan-activation instruction includes an instruction for starting touch scan at intervals shorter than the given length of time, and

wherein upon receipt of the touch-scan-activation instruction, the processor performs a coordinate calculation of a touch position based on touch detection signals obtained by the touch panel.

15. The electronic device according to claim 12 , wherein the touch panel controller has:

a plurality of drive terminals connected with the first group of electrodes of the touch panel;

a first drive circuit operable to output a drive pulse from the drive terminals;

a plurality of detection terminals connected with the second group of electrodes of the touch panel;

a second drive circuit operable to output a drive pulse to the detection terminals;

a detection circuit operable to accumulate signals input, more than once, through the detection terminals in synchronization with a change in the drive pulse thereby creating detection data; and

a timing control circuit operable to control a touch-detecting action by use of the first and second drive circuits and the detection circuit, and

wherein the timing control circuit has

a first touch detection mode in which detection data are created by accumulating, by use of the detection circuit, signals input more than once from the detection terminals in synchronization with a change of the drive pulse output by the first drive circuit, and

a second touch detection mode in which detection data are created by accumulating, by use of the detection circuit, signals input more than once from the detection terminals of one of groups consisting of the even and odd detection terminals respectively in synchronization with a change of the drive pulse output from the second drive circuit through the detection terminals of the other group.

16. The electronic device according to claim 15 ,

wherein the action of detecting a touch/no touch which the processor returns to its workable state from the sleep state to cause the touch panel controller to perform each time the given length of time elapses is an action according to the second touch detection mode.

17. The electronic device according to claim 16 ,

wherein the processor in the sleep state returns to its workable state from the sleep state each time the given length of time elapses,

wherein, when acquiring the result of judgment as “being touched”, the processor makes a request for interrupt to the host processor, and waits for a touch-scan-activation instruction from the touch panel controller, and the display driver waits for an activation instruction from the host processor, and

wherein the touch-detecting action in response to the touch-scan-activation instruction is an action according to the first touch detection mode.

18. The electronic device according to claim 17 , wherein a touch condition when the processor judges as “being touched” in the second touch detection mode is that more than one touch position can be detected.

19. The electronic device according to claim 18 ,

wherein the touch-scan-activation instruction includes an instruction for starting touch scan at intervals shorter than the given length of time, and

wherein upon receipt of the touch-scan-activation instruction, the processor performs a coordinate calculation of a touch position based on touch detection signals obtained by the touch panel.

20. The electronic device according to claim 15 , wherein the timing control circuit has a mode register which receives, from the host processor, instruction data for providing an instruction on which of the first and second touch detection modes to select, and rewritably stores the instruction data.

21. The electronic device according to claim 15 , wherein the timing control circuit has a mode register which receives, from the host processor, instruction data for providing an instruction on which group of the even and odd detection terminal groups to direct the drive pulse to, and on which group to accept detection signal input from, and rewritably stores the instruction data.