Electronic device and method for controlling electronic device

1. An electronic device, comprising:

n (n is an integer greater than or equal to 2) physical layer control units which communicate with an other apparatus connected to the device itself and control a physical layer;

a logical layer control unit which controls a logical layer in communication with the other apparatus; and

a control unit which controls the logical layer control unit from a power-supply ON state to a standby state in accordance with a standby instruction for the device itself,

wherein one physical layer control unit of the n physical layer control units generates a clock using a connected resonator, and another physical layer control unit receives the clock generated by the physical layer control unit to which the resonator is connected, and

wherein the n physical layer control units are connected in series in a daisy chain connection through a signal line of the clock, and a physical layer control unit of a last stage connected in the daisy chain connection and the logical layer control unit are connected through the signal line of the clock.

2. The electronic device according to claim 1 , wherein the control unit controls the logical layer control unit from the standby state to the power-supply ON state in accordance with a shift instruction from the standby state to the power-supply ON state for the device itself.

3. The electronic device according to claim 1 , wherein

the clock generated by the physical layer control unit of a first stage to which the resonator is connected is output to a physical layer control unit of a second stage,

wherein physical layer control units of second to (n−1) th stages receive the clock output from physical layer control units of previous stages and output the received clock to physical layer control units of next stages, and

wherein the physical layer control unit of an n th stage, which is the last stage connected in the daisy chain connection, receives the clock output from the physical layer control unit of the (n−1) th stage and outputs the received clock to the logical layer control unit.

4. The electronic device according to claim 1 , further comprising a second switch which switches control signals between the n physical layer control units and the logical layer control unit,

wherein the control unit switches the second switch so that the control signal output from the logical layer control unit is not supplied to the physical layer control unit to be controlled from the power-supply ON state to the standby state in accordance with the standby instruction for the device itself.

5. The electronic device according to claim 4 , wherein the control unit switches the second switch so that the control signal input to the second switch is not supplied to a physical layer control unit in non-communication with the other apparatus among the plurality of physical layer control units.

6. The electronic device according to claim 1 , wherein the clock generated by the physical layer control unit of a first stage to which the resonator is connected is output to a physical layer control unit of a second stage.

7. The electronic device according to claim 6 , wherein physical layer control units of second to (n−1) th stages receive the clock output from physical layer control units of previous stages and output the received clock to physical layer control units of next stages.

8. The electronic device according to claim 7 , wherein the physical layer control unit of an n th stage receives the clock output from the physical layer control unit of the (n−1) th stage and outputs the received clock to the logical layer control unit.

9. The electronic device according to claim 1 , wherein physical layer control units of second to (n−1) th stages receive the clock output from physical layer control units of previous stages and output the received clock to physical layer control units of next stages.

10. The electronic device according to claim 1 , wherein a physical layer control unit of an n th stage receives the clock output from a physical layer control unit of (n−1) th stage and outputs the received clock to the logical layer control unit.

11. An electronic device comprising:

n (n is an integer greater than or equal to 2) physical layer control units which communicate with an other apparatus connected to the device itself and control a physical layer, wherein one of the n physical layer control units is connected to a resonator to generate a clock;

a logical layer control unit which controls a logical layer in communication with the other apparatus;

a control unit which controls the physical layer control unit to which the resonator is not connected and the logical layer control unit from a power-supply ON state to a standby state in accordance with a standby instruction for the device itself; and

a first switch which receives the clock from the physical layer control unit to which the resonator is connected and switches from supplying the clock to the physical layer control units to which the resonator is not connected and the logical layer control unit to not supplying the clock in accordance with the standby instruction for the device itself.

12. The electronic device according to claim 11 , wherein the control unit switches the first switch so that the clock input to the first switch is not supplied to a physical layer control unit in non-communication with the other apparatus among the plurality of physical layer control units.

13. The electronic device according to claim 11 , wherein the control unit switches the first switch at a timing before a timing at which a second switch which switches control signals between the n physical layer control units and the logical layer control unit is switched in accordance with the standby instruction for the device itself.

14. The electronic device according to claim 11 , further comprising a second switch which switches control signals between the n physical layer control units and the logical layer control unit,

wherein the control unit switches the second switch so that the control signal output from the logical layer control unit is not supplied to the physical layer control unit to be controlled from the power-supply ON state to the standby state in accordance with the standby instruction for the device itself.

15. The electronic device according to claim 14 , wherein the control unit switches the second switch so that the control signal input to the second switch is not supplied to a physical layer control unit in non-communication with the other apparatus among the plurality of physical layer control units.

16. The electronic device according to claim 11 , further comprising a second switch which switches control signals between the n physical layer control units and the logical layer control unit,

wherein the control unit switches the second switch so that the control signal input to the second switch is not supplied to a physical layer control unit in non-communication with the other apparatus among the plurality of physical layer control units.

17. The electronic device according to claim 11 , wherein the n physical layer control units are connected in series in a daisy chain connection through a signal line of a clock.

18. The electronic device according to claim 17 , wherein a physical layer control unit of a last stage connected in the daisy chain connection and the logical layer control unit are connected through the signal line of the clock.

19. The electronic device according to claim 18 , wherein the clock generated by the physical layer control unit of a first stage to which a resonator is connected is output to a physical layer control unit of a second stage.

20. A method for controlling an electronic device, the electronic device comprising n (n is an integer greater than or equal to 2) physical layer control units which communicate with an other apparatus connected to the device itself and control a physical layer and a logical layer control unit which controls a logical layer in communication with the other apparatus, the method comprising:

generating a clock using a resonator connected to one physical layer control unit among the n physical layer control units;

controlling the physical layer control unit to which the resonator is not connected and the logical layer control unit from a power-supply ON state to a standby state in accordance with a standby instruction for the device itself; and

switching from supplying the clock from the physical layer control unit to which the resonator is connected to the physical layer control units to which the resonator is not connected and the logical layer control unit to not supplying the clock in accordance with the standby instruction for the device itself.