Electronic apparatus, category determination method for transmission cable and transmission cable

1. An electronic apparatus, comprising:

a receptacle having a plurality of pins for connecting a plug of a transmission cable; and

transmission cable determination circuitry configured to apply a predetermined voltage to a predetermined plurality of pins of the plurality of pins of said receptacle and to determine a category of the transmission cable,

wherein the transmission cable determination circuitry determines the category of the transmission cable based on a detection performed by the transmission cable determination circuitry, the detection performed by the transmission cable determination circuitry being performed after the application of the predetermined voltage to the predetermined plurality of pins of the plurality of pins of said receptacle, and

wherein the transmission cable determination circuitry applies the predetermined voltage to the predetermined plurality of pins of the plurality of pins of said receptacle in order to determine the category of the transmission cable.

2. The electronic apparatus according to claim 1 , wherein said transmission cable determination circuitry

determines the category of the transmission cable based on whether or not current flows through the predetermined pin when the predetermined voltage is applied to the predetermined pin of said receptacle.

3. The electronic apparatus according to claim 1 , wherein said transmission cable determination circuitry

determines the category of the transmission cable based on the magnitude of current flowing through the predetermined pin when the predetermined voltage is applied to the predetermined pin of said receptacle.

4. The electronic apparatus according to claim 1 , wherein said transmission cable determination circuitry determines the category of the transmission cable by successively applying the predetermined voltage to the predetermined plurality of pins of said receptacle.

5. The electronic apparatus according to claim 1 , wherein the transmission cable transmits a digital signal in the form of differential signals, and

said transmission cable determination circuitry applies the predetermined voltage to the predetermined pin of said receptacle to determine which one of a first category and a second category, which use different numbers of channels of differential signals from each other, is the category of the transmission cable.

6. The electronic apparatus according to claim 1 , further comprising:

digital signal transmission circuitry configured to transmit a digital signal to an external apparatus through the transmission cable; and

an operation controlling circuitry configured to control operation of said digital signal transmission circuitry based on a result of the determination of said transmission cable determination circuitry.

7. The electronic apparatus according to claim 6 , wherein said digital signal transmission circuitry has a first operation mode and a second operation mode in which said digital signal transmission circuitry transmits a digital signal in the form of differential signals to the external apparatus through a transmission line such that the number of channels of the differential signals in the first operation mode is a first number and the number of channels of the differential signals in the second operation mode is a second number which is greater than the first number, and

said transmission cable determination circuitry applies the predetermined voltage to the predetermined pin of said receptacle to determine whether the category of the transmission cable is a first category which is ready for the first operation mode and a second category which is ready for the second operation mode.

8. The electronic apparatus according to claim 1 , wherein the category of the transmission cable indicates a difference in physical structure.

9. The electronic apparatus according to claim 1 , wherein the category of the transmission cable indicates a difference in compensated transmission band.

10. The electronic apparatus according to claim 1 , wherein the category of the transmission cable indicates a difference in value of current which can be supplied through the transmission cable.

11. The electronic apparatus according to claim 1 , wherein the category of the transmission cable indicates a difference in presence/absence of an equalizer.

12. A category determination method for a transmission cable, comprising:

applying, by transmission cable determination circuitry, a predetermined voltage to a predetermined plurality of pins of a receptacle, which has a plurality of pins for connecting a plug of a transmission cable;

determining, by the transmission cable determination circuitry, the category of the transmission cable,

wherein the transmission cable determination circuitry determines the category of the transmission cable based on a detection performed by the transmission cable determination circuitry, the detection performed by the transmission cable determination circuitry being performed after the application of the predetermined voltage to the predetermined plurality of pins of said receptacle, and

wherein the transmission cable determination circuitry applies the predetermined voltage to the predetermined plurality of pins of said receptacle in order to determine the category of the transmission cable.

13. An electronic apparatus, comprising:

digital signal transmission circuitry having a first operation mode and a second operation mode in which said digital signal transmission circuitry transmits a digital signal in the form of differential signals to the external apparatus through a transmission line such that the number of channels of the differential signals in the first operation mode is a first number and the number of channels of the differential signals in the second operation mode is a second number which is greater than the first number;

a receptacle having a plurality of pins for connecting a plug of the transmission cable;

transmission cable determination circuitry configured to apply a predetermined voltage to a predetermined one of the pins of said receptacle to determine whether the category of the transmission cable is a first category which is ready for the first operation mode and a second category which is ready for the second operation mode; and

operation controlling circuitry configured to control operation of said digital signal transmission circuitry based on a result of the determination of said transmission cable determination circuitry.