Signal processing unit

• US 8,446,171 B2
• Filed: 04/23/2012
• Issued: 05/21/2013
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takahashi, Yasuyuki
• Primary Examiner(s): TRAN, ANH Q
• Application Number:
  US13/453,160
• Publication Number:
  US 20120274356A1
• Time in Patent Office: 393 Days
• Field of Search: None
• US Class Current: 326/46
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H03K 19/0013 in field effect transistor circuits
• CPC Class Codes: H03K 19/00315 in field-effect transistor circuits
• CPC Class Codes: H10B 12/05 Making the transistor
• CPC Class Codes: H10B 12/50 Peripheral circuit region structures
• CPC Class Codes: H10B 69/00 Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices
• CPC Class Codes: H10B 99/00 Subject matter not provided for in other groups of this subclass

Abstract

A signal processing unit with reduced power consumption is provided. A transistor in which a channel is formed in an oxide semiconductor is used for a storage circuit included in the signal processing unit, so that data can be held (stored) even while supply of power is stopped. Non-destructive reading can be performed on the data stored in the storage circuit even when supply of power to the signal processing unit is stopped.

Claims

1. A semiconductor device comprising:

a logic circuit to which a first power supply potential is supplied;

a storage circuit comprising a capacitor and a transistor; and

a reading circuit to which a second power supply potential is supplied,

wherein the transistor comprises an oxide semiconductor,

wherein one of a source and a drain of the transistor is electrically connected to the logic circuit,

wherein the other of the source and the drain of the transistor is electrically connected to one of the electrodes of the capacitor, and

wherein the other of the source and the drain of the transistor is electrically connected to the reading circuit.

2. The semiconductor device according to claim 1, wherein a gate of the transistor is electrically connected to the logic circuit.

3. The semiconductor device according to claim 1, wherein the first power supply potential is supplied from a first power source and the second power supply potential is supplied from a second power source.

4. The semiconductor device according to claim 1, wherein the first power supply potential and the second power supply potential are supplied from a power source via a power distribution circuit.

5. The semiconductor device according to claim 1, wherein the oxide semiconductor comprises In and one or more of elements selected from Sn, Zn, Ga, Al, Mn, and Co.

6. The semiconductor device according to claim 1, wherein the oxide semiconductor includes crystal.

7. An electronic device including the semiconductor device according to claim 1.

8. A semiconductor device comprising:

a power supply circuit;

a logic circuit; and

a storage circuit,

wherein the storage circuit comprises a capacitor and a transistor,

wherein the transistor is configured to control supply, holding, and release of charge in the capacitor,

wherein the power supply circuit is configured to supply power to the logic circuit and the storage circuit,

wherein the logic circuit is configured to store an arithmetic result of a signal input to the logic circuit in the storage circuit, and

wherein the storage circuit is configured to hold the arithmetic result even while supply of power is stopped in such a manner that the transistor is turned off before supply of power from the power supply circuit is stopped.

9. The semiconductor device according to claim 8, wherein the transistor comprises an oxide semiconductor.

10. The semiconductor device according to claim 9, wherein the oxide semiconductor comprises In and one or more of elements selected from Sn, Zn, Ga, Al, Mn, and Co.

11. The semiconductor device according to claim 9, wherein the oxide semiconductor includes crystal.

12. An electronic device including the semiconductor device according to claim 8.

13. A semiconductor device comprising:

a power supply circuit;

a logic circuit;

a storage circuit, and

a reading circuit electrically connected to the storage circuit,

wherein the storage circuit comprises a capacitor and a transistor,

wherein the transistor is configured to control supply, holding, and release of charge in the capacitor,

wherein the power supply circuit is configured to supply power to the logic circuit and the storage circuit,

wherein the logic circuit is configured to store an arithmetic result of a signal input to the logic circuit in the storage circuit, and

wherein the storage circuit is configured to hold the arithmetic result even while supply of power is stopped in such a manner that the transistor is turned off before supply of power from the power supply circuit is stopped, and

wherein the arithmetic result held in the storage circuit is detected by the reading circuit.

14. The semiconductor device according to claim 13, wherein the arithmetic result held in the storage circuit is detected even while supply of power is stopped.

15. The semiconductor device according to claim 13, wherein the reading circuit is connected to a second power supply circuit.

16. The semiconductor device according to claim 13, wherein the transistor comprises an oxide semiconductor.

17. The semiconductor device according to claim 16, wherein the oxide semiconductor comprises In and one or more of elements selected from Sn, Zn, Ga, Al, Mn, and Co.

18. The semiconductor device according to claim 16, wherein the oxide semiconductor includes crystal.

19. An electronic device including the semiconductor device according to claim 13.