Semiconductor device and data processing system

• US 8,499,182 B2
• Filed: 02/21/2011
• Issued: 07/30/2013
• Est. Priority Date: 02/22/2010
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Fujigaya, Masaki
• Primary Examiner(s): Stoynov, Stefan
• Application Number:
  US13/031,489
• Publication Number:
  US 20110208987A1
• Time in Patent Office: 890 Days
• Field of Search: 713/320, 713/323, 713/324, 455/574
• US Class Current: 713/323
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A semiconductor device has reduced power consumption and processing time associated with the release of a low power consumption state set by a central processing unit thereof. The semiconductor device controls a relationship between a forcible release and reset of the low power consumption state previously set by the central processing unit. In one embodiment, a forcible release control circuit forcibly releases the supply and stop of power and clocks previously set to one or more controlled circuits, only during a period required by a signal outputted from a requesting circuit, which requesting circuit may be either internal to the device or external to the device. Once the request signal from the requesting circuit has ended, the controlled circuits and, if appropriate, the central processing unit as well, are restored to the original low power consumption state.

Claims

1. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which control the stop and supply of the power and clocks relative to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks that are conducted on one or more predetermined controlled circuits by the power and clock control circuits, only during a period required by a power and clock request signal outputted from a requesting circuit, to thereby temporarily resume supply of the power and clocks to the one or more predetermined controlled circuits and thus enable operation of at least one resource required by the requesting circuit.

2. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which control the stop and supply of the power and clocks relative to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks that are conducted on one or more predetermined controlled circuits by the power and clock control circuits, only during a period required by a power and clock request signal outputted from a requesting circuit;

wherein the power and clock control circuits comprise;

control registers which hold control data for controlling the stop and supply of the power and clocks to the plurality of the controlled circuits, and

control logics which input the control data in the control registers and an instruction signal to the forcible release control circuit to thereby control the supply and stop of the power and clocks relative to the controlled circuits, and

wherein each of the control logics;

allows the power and clocks to be supplied when the control data indicates the supply of the power and clocks,

allows the power and clocks to stop when the control data indicates the stop of the power and clocks and the power and clock request signal indicates no request for the supply of the power and clocks, and

allows the power and clocks to be supplied when the control data indicates the stop of the power and clocks and the power and clock request signal requests the supply of the power and clocks.

3. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which control the stop and supply of the power and clocks relative to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks that are conducted on one or more predetermined controlled circuits by the power and clock control circuits, only during a period required by a power and clock request signal outputted from a requesting circuit;

wherein the forcible release control circuit receives state signals each indicative of a state of the supply and stop of power and clocks to the controlled circuits from the power and clock control circuits and controls a first timing provided to release the supply and stop of the power and clocks and a second timing provided to restore the same from the release, referring to the received state signals.

4. The semiconductor device according to claim 3, wherein the forcible release control circuit controls a first timing provided to release the supply and stop of the power and clocks and a second timing provided to restore the same from the release, using a timer.

5. The semiconductor device according to claim 3, further comprising an interrupt controller which causes the power and clock control circuits to resume the supply of power and clocks to the central processing unit whose supply has been stopped, in response to an interrupt request supplied from the requesting circuit.

6. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which control the stop and supply of the power and clocks relative to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit;

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks that are conducted on one or more predetermined controlled circuits by the power and clock control circuits, only during a period required by a power and clock request signal outputted from a requesting circuit; and

an interrupt controller which causes the power and clock control circuits to resume the supply of power and clocks to the central processing unit whose supply has been stopped, in response to an interrupt request supplied from the requesting circuit;

wherein the requesting circuit comprises a data processing circuit for processing data fetched therein, and

wherein said one or more predetermined controlled circuits comprises a first interface circuit for supplying data to be fetched into the requesting circuit, based on a request issued from the requesting circuit.

7. The semiconductor device according to claim 6, further comprising a second interface circuit which obtains data to be supplied to the requesting circuit by said one or more predetermined controlled circuits, through the control of the central processing unit.

8. The semiconductor device according to claim 7,

wherein the data processing circuit comprises a DMAC, a buffer memory which retains data captured by the DMAC, and an arithmetic circuit which performs arithmetic processing on the data fetched into the buffer memory,

wherein the first interface circuit comprises a memory controller which controls a memory coupled to the outside of the semiconductor device, and

wherein the second interface circuit comprises a file memory controller which controls a file memory coupled to the outside of the semiconductor device.

9. A data processing system comprising:

the semiconductor device according to claim 8;

a memory coupled to the memory controller included in the semiconductor device from the outside of the semiconductor device; and

a file memory coupled to the file memory controller included in the semiconductor device from the outside of the semiconductor device.

10. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which respectively control the stop and supply of the power and clocks to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks, conducted on one or more predetermined controlled circuits by the power and clock control circuits only during a period required by a power and clock request signal received at a first external input terminal of the semiconductor device, to thereby temporarily resume supply of the power and clocks to the one or more predetermined controlled circuits and thus enable operation of at least one resource required by an external circuit issuing said request signal.

11. The semiconductor device according to claim 10,

wherein the one or more predetermined controlled circuits comprise a first controlled circuit controlled from the outside of the semiconductor device and a second controlled circuit controlled by the first controlled circuit.

12. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which respectively control the stop and supply of the power and clocks to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks, conducted on one or more predetermined controlled circuits by the power and clock control circuits only during a period required by a power and clock request signal received at a first external input terminal of the semiconductor device;

wherein the power and clock control circuits comprise;

control registers which hold control data for controlling the stop and supply of power and clocks to the plurality of the controlled circuits, and

control logics which respectively input the control data in the control registers and an instruction signal to the forcible release control circuit to thereby control the supply and stop of the power and clocks to the controlled circuits, and

wherein each of the control logics;

allows the power and clocks to be supplied when the control data indicates the supply of the power and clocks,

allows the power and clocks to stop when the control data indicates the stop of the power and clocks and the power and clock request signal indicates no request for the supply of the power and clocks, and

allows the power and clocks to be supplied when the control data indicates the stop of the power and clocks and the power and clock request signal requests the supply of the power and clocks.

13. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which respectively control the stop and supply of the power and clocks to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks, conducted on one or more predetermined controlled circuits by the power and clock control circuits only during a period required by a power and clock request signal received at a first external input terminal of the semiconductor device;

wherein the predetermined controlled circuit comprises a slave interface circuit which is slave-interface operated with respect to an external device which functions as a requesting circuit and produces the power and clock request signal received at the first external input terminal.

14. The semiconductor device according to claim 13, further comprising an interrupt controller which causes the power and clock control circuits to resume the supply of power and clocks to the central processing unit whose supply has been stopped, in response to an interrupt request received at a second external input terminal.

15. A data processing system comprising:

the semiconductor device according to claim 14, wherein;

the slave interface circuit is included in the semiconductor device; and

the external device is coupled to the first external input terminal and the second external input terminal.

16. A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which respectively control the stop and supply of the power and clocks to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks, conducted on one or more predetermined controlled circuits by the power and clock control circuits only during a period required by a power and clock request signal received at a first external input terminal of the semiconductor device;

wherein the one or more predetermined controlled circuits comprise a first controlled circuit controlled from the outside of the semiconductor device and a second controlled circuit controlled by the first controlled circuit;

wherein the first controlled circuit comprises a slave interface circuit which is slave-interface operated by an external data processing device coupled to the first external input terminal, and

wherein the second controlled circuit comprises a memory interface circuit controlled by the slave interface circuit and the central processing unit.

17. The semiconductor device according to claim 16, further comprising an interrupt controller which causes the power and clock control circuits to resume the supply of power and clocks to the central processing unit whose supply has been stopped, in response to an interrupt request received at a second external input terminal.

18. A data processing system comprising:

the semiconductor device according to claim 17;

wherein;

the external data processing device is coupled to the first external terminal and also to the second external terminal; and

an external memory device is coupled to the memory interface circuit.

19. The

A semiconductor device comprising:

a central processing unit for controlling a stop and supply of power and clocks, and for executing instructions;

a plurality of controlled circuits subject to control of the stop and supply of the power and clocks;

power and clock control circuits which respectively control the stop and supply of the power and clocks to the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases the supply and stop of the power and clocks, conducted on one or more predetermined controlled circuits by the power and clock control circuits only during a period required by a power and clock request signal received at a first external input terminal of the semiconductor device;

wherein the one or more predetermined controlled circuits comprise a first controlled circuit controlled from the outside of the semiconductor device and a second controlled circuit controlled by the first controlled circuit;

wherein the first controlled circuit comprises a slave interface circuit which is slave-interface operated by an external data processing device coupled to the first external input terminal, and

wherein the second controlled circuit comprises an internal memory controlled by the slave interface circuit and the central processing unit.

20. The semiconductor device according to claim 19, further comprising an interrupt controller which causes the power and clock control circuits to resume the supply of power and clocks to the central processing unit whose supply has been stopped, in response to an interrupt request received at a second external input terminal.

21. A data processing system comprising:

the semiconductor device according to claim 20;

wherein;

the external data processing device is coupled to the first external terminal and also to the second external terminal.

22. A semiconductor device comprising:

a central processing unit for controlling a setting and release of a low power consumption state, and for executing instructions;

a plurality of controlled circuits each subject to control of a setting and release of a low power consumption state;

a low power consumption control circuit which controls the setting and release of the low power consumption state to and from the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases a low power consumption state set to a predetermined controlled circuit by the low power consumption control circuit only during a period required by a request signal outputted from a requesting circuit, to thereby temporarily resume power to said predetermined controlled circuit and thus enable operation of at least one resource required by the requesting circuit.

23. A semiconductor device comprising:

a central processing unit for controlling a setting and release of a low power consumption state, and for executing instructions;

a plurality of controlled circuits each subject to control of a setting and release of a low power consumption state;

a low power consumption control circuit which controls the setting and release of the low power consumption state to and from the central processing unit and the controlled circuits, based on execution of one or more instructions by the central processing unit; and

a forcible release control circuit which forcibly releases a low power consumption state set to a predetermined controlled circuit by the low power consumption control circuit only during a period required by a request signal received at a first external input terminal, to thereby temporarily resume power to said predetermined controlled circuit and thus enable operation of at least one resource required by an external circuit issuing said request signal.

24. A semiconductor device comprising:

a central processing unit (CPU) configured to execute instructions and capable of entering a low power consumption state in response to one or more of said instructions;

a plurality of controlled circuits, each capable of being placed in a low power consumption state in response to one or more of said instructions;

a forcible release control circuit configured to;

receive a request signal from a requesting circuit; and

in response to the request signal and only during a period required by the request signal, release a first low power consumption state of a predetermined one of said plurality of controlled circuits which has been placed in the first low power consumption state by the CPU, so that the requesting circuit is able to use said predetermined one of said plurality of controlled circuits; and

an interrupt controller configured to;

receive an interrupt request from said requesting circuit; and

in response to the interrupt request, output at least one signal to restore the CPU to an operable state from a second low power consumption state of the CPU.

25. The semiconductor device according to claim 24, wherein:

the forcible release control circuit is configured to receive a plurality of state signals indicative of a power consumption state of one or more of said plurality of controlled circuits; and

in response to said plurality of state signals, the forcible release control circuit is configured to output an activated signal to the requesting circuit to indicate that the requesting circuit can use said predetermined one of said plurality of controlled circuits.

26. The semiconductor device according to claim 24, wherein the forcible release control circuit comprises a timer configured to:

provide a first timing to release the first low power consumption state of said predetermined one of said plurality of controlled circuits, and

provide a second timing to restore the first low power consumption state of said predetermined one of said plurality of controlled circuits.

27. The semiconductor device according to claim 24, wherein:

the requesting circuit comprises a signal processing unit (SPU) internal to the semiconductor device and configured to output the request signal received by the forcible release control circuit; and

the SPU is configured to process audio data and output an audio signal.

28. The semiconductor device according to claim 24, wherein:

the request signal is received by the forcible release control circuit at a first external input terminal of the semiconductor device.

29. The semiconductor device according to claim 28, in combination with a data processing device which:

functions as the requesting circuit;

is coupled to the first external input terminal of the semiconductor device, and

is configured to output said request signal to the forcible control release circuit.

30. The semiconductor device according to claim 29, wherein:

the data processing device is coupled to a second external input terminal of the semiconductor device, and configured to output said interrupt request to the interrupt controller.

31. The semiconductor device according to claim 29, wherein:

said predetermined one of said plurality of controlled circuits comprises a slave interface circuit which is slave-interface operated with respect to the data processing device; and

the data processing device is configured to access a memory external to the semiconductor device via the slave interface circuit.

32. The semiconductor device according to claim 31, wherein:

said predetermined one of said plurality of controlled circuits further comprises a memory interface circuit; and

the data processing device is configured to access said memory external to the semiconductor device via the slave interface circuit and the memory interface circuit.

33. The semiconductor device according to claim 29, wherein:

said predetermined one of said plurality of controlled circuits comprises a slave interface circuit which is slave-interface operated with respect to the data processing device; and

the data processing device is configured to access a memory internal the semiconductor device via the slave interface circuit.

34. A semiconductor device comprising:

a requesting circuit configured to output a first request signal;

a central processing unit (CPU) configured to execute instructions and selectively occupy a low power consumption state;

a plurality of controlled circuits, each configured to selectively occupy a low power consumption state;

a forcible release control circuit configured to;

receive the first request signal from the requesting circuit; and

in response to the first request signal, release a low power consumption state of a first controlled circuit assembly comprising one or more controlled circuits so that the requesting circuit is capable of accessing said first controlled circuit assembly; and

an interrupt controller configured to;

receive an interrupt request from said requesting circuit; and

in response to the interrupt request, output at least one signal to restore the CPU to an operable state from a low power consumption state of the CPU;

wherein;

following receipt of the interrupt request, a low power consumption state of a second controlled circuit assembly is released, the second controlled circuit assembly comprising one or more controlled circuits, at least one of which is different from the one or more controlled circuits belonging to the first controlled circuit assembly; and

in the operable state, the CPU is capable of accessing the second controlled circuit assembly.

35. The semiconductor device according to claim 34, wherein:

the forcible release control circuit is further configured to resume the low power consumption state of said first controlled circuit assembly, after the requesting circuit has accessed said first controlled circuit assembly; and

the CPU resumes the low power consumption state of the CPU, after the CPU has accessed the second controlled circuit assembly.

36. The semiconductor device according to claim 34, wherein, without restoring the CPU to the operable state from the low power consumption state of the CPU:

the low power consumption state of the first controlled circuit assembly is released; and

the requesting circuit accesses the first controlled circuit assembly.

37. The semiconductor device according to claim 34, wherein:

the first controlled circuit assembly and the second controlled circuit assembly are disjoint and have no controlled circuits in common; and

in the operable state, the CPU is capable of accessing both the second controlled circuit assembly and the first controlled circuit assembly.

38. The semiconductor device according to claim 37, wherein:

if the CPU is restored to the operable state pursuant to an interrupt request while the requesting circuit is accessing the first controlled circuit assembly, the forcible release control circuit does not resume the low power consumption state of the first controlled circuit assembly even after the requesting circuit has finished access thereto.

39. The semiconductor device according to claim 34, further comprising:

a first memory associated with the requesting circuit;

a second memory configured to supply first data to the first memory via a first interface circuit which belongs to the first controlled circuit assembly; and

a third memory configured to supply second data to the second memory via a second interface circuit which belongs to the second controlled circuit assembly, wherein;

even when the CPU is in the low power consumption state of the CPU, the first data is supplied from the second memory to the first memory following receipt of the first request signal at the forcible release control circuit.

40. The semiconductor device according to claim 39, wherein:

the second data is supplied from the third memory to the second memory only when the CPU is in the operable state, after receipt of the interrupt request at the interrupt controller.