Electronic apparatus and its control method, and accessory and its control method
An accessory includes a plurality of communication contacts that includes a first contact, and a control unit that notifies an electronic apparatus of a communication request by changing a signal level of the first contact from a first signal level to a second signal level different from the first signal level, and transmits information indicating a communication factor in response to a reception of a request for the information indicating the communication factor in response to a notification of the communication request. In a case where the control unit notifies the electronic apparatus of the communication request via the first contact in response to a start of a power supply, the control unit performs predetermined communication without receiving the request for the information indicating the communication factor or transmitting the information indicating the communication factor.
1. An accessory attachable to and detachable from an electronic apparatus, the accessory comprising:
a plurality of communication contacts that includes a first contact;
at least one processor; and
at least one memory coupled to the at least one processor storing instructions that, when executed by the at least one processor, cause the at least one processor to function as a control unit configured to control communication with the electronic apparatus via the plurality of communication contacts,
wherein in a case where the control unit changes a signal level of the first contact from a first signal level to a second signal level different from the first signal level in response to a start of a power supply, the control unit performs a predetermined communication different from a communication performed in a case where the control unit changes the signal level of the first contact from the first signal level to the second signal level in response to a factor different from the start of the power supply,
wherein in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply, the control unit performs communication with the electronic apparatus using information indicating a communication factor,
wherein in a case where the signal level of the first contact is changed from the second signal level to the first signal level in response to a factor different from the start of the power supply, the control unit does not perform communication with the electronic apparatus using information indicating a communication factor.
2. The accessory according to claim 1 , wherein the predetermined communication includes a reception of a request for attribute information on the accessory, and a transmission of the attribute information on the accessory.
3. The accessory according to claim 2 , wherein the attribute information on the accessory includes information on a communication method for receiving a request for information indicating the communication factor and for transmitting the information indicating the communication factor.
4. The accessory according to claim 3 , wherein in a case where the information on the communication method indicates first information, the control unit executes, by I2C communication, the reception of the request for the information indicating the communication factor and the transmission of the information indicating the communication factor.
5. The accessory according to claim 4 , wherein in synchronization with a clock signal received via a second contact in the I2C communication, the control unit receives the request for the information indicating the communication factor and transmits the information indicating the communication factor via a third contact.
6. The accessory according to claim 5 , wherein the power supply is started in response to a change in a signal level of a fourth contact.
7. The accessory according to claim 6 , wherein the power supply is started in response to powering-on of the electronic apparatus or an attachment of the accessory to the electronic apparatus.
8. The accessory according to claim 4 , wherein in a case where the information on the communication method indicates second information, the control unit executes, by SPI communication, the reception of the request for the information indicating the communication factor and the transmission of the information indicating the communication factor.
9. The accessory according to claim 2 , wherein in response to a notification of a communication request by changing the signal level of the first contact from the first signal level to the second signal level in response to the start of the power supply, the control unit executes, by I2C communication, the reception of the request for the attribute information on the accessory and the transmission of the attribute information on the accessory.
10. The accessory according to claim 1 , wherein in a case where the control unit notifies the electronic apparatus of a communication request by changing the signal level of the first contact from the first signal level to the second signal level for a first time after the power supply is started, the control unit performs the predetermined communication without receiving a request for information indicating the communication factor or transmitting the information indicating the communication factor.
11. A system comprising:
an electronic apparatus;
the accessory according to claim 1 attachable to and detachable from the electronic apparatus.
12. An electronic apparatus attachable to and detachable from an accessory, the electronic apparatus comprising:
a plurality of communication contacts that includes a first contact;
at least one processor; and
at least one memory coupled to the at least one processor storing instructions that, when executed by the at least one processor, cause the at least one processor to function as a control unit configured to control communication with the accessory via the plurality of communication contacts,
wherein in a case where a signal level of the first contact is changed from a first signal level to a second signal level different from the first signal level in response to a start of a power supply, the control unit performs a predetermined communication different from a communication performed in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply;
wherein in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply, the control unit performs communication with the accessory using information indicating a communication factor,
wherein in a case where the signal level of the first contact is changed from the second signal level to the first signal level in response to a factor different from the start of the power supply, the control unit does not perform communication with the accessory using information indicating a communication factor.
13. The electronic apparatus according to claim 12 , wherein the predetermined communication includes a transmission of a request for attribute information on the accessory and a reception of the attribute information on the accessory.
14. The electronic apparatus according to claim 13 , wherein the attribute information on the accessory includes information on a communication method for transmitting a request for information indicating the communication factor and for receiving the information indicating the communication factor.
15. The electronic apparatus according to claim 14 , wherein in a case where the information on the communication method indicates first information, the control unit executes, by I2C communication, the transmission of the request for the information indicating the communication factor and the reception of the information indicating the communication factor.
16. The electronic apparatus according to claim 15 , wherein in synchronization with a clock signal received via a second contact in the I2C communication, the control unit transmits the request for the information indicating the communication factor and receives the information indicating the communication factor via a third contact.
17. The electronic apparatus according to claim 16 , wherein the power supply is started in response to a change in a signal level of a fourth contact.
18. The electronic apparatus according to claim 17 , wherein the power supply is started in response to powering-on of the electronic apparatus or an attachment of the accessory to the electronic apparatus.
19. The electronic apparatus according to claim 15 , wherein in a case where the information on the communication method indicates second information, the control unit executes, by SPI communication, the transmission of the request for the information indicating the communication factor and the reception of the information indicating the communication factor.
20. The electronic apparatus according to claim 13 , wherein in response to a notification of a communication request by changing the signal level of the first contact from the first signal level to the second signal level in response to the start of the power supply, the control unit executes, by I2C communication, the transmission of the request for the attribute information on the accessory and the reception of the attribute information on the accessory.
21. The electronic apparatus according to claim 12 , wherein in a case where the control unit is notified a communication request by changing the signal level of the first contact from the first signal level to the second signal level for a first time after the power supply is started, the control unit performs the predetermined communication without receiving a request for information indicating the communication factor or transmitting the information indicating the communication factor.
22. A system comprising:
the electronic apparatus according to claim 12 ; and
an accessory attachable to and detachable from the electronic apparatus.
23. A control method of an accessory that is attachable to and detachable from an electronic apparatus and includes a plurality of communication contacts that includes a first contact, the control method comprising the steps of:
in a case where a signal level of the first contact is changed from a first signal level to a second signal level different from the first signal level in response to a start of a power supply, performing a predetermined communication different from a communication performed in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply,
wherein in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply, performing communication with the electronic apparatus using information indicating a communication factor,
wherein in a case where the signal level of the first contact is changed from the second signal level to the first signal level in response to a factor different from the start of the power supply, not performing communication with the electronic apparatus using information indicating a communication factor.
24. A non-transitory computer-readable storage medium storing a program that causes a computer of an accessory that is attachable to and detachable from an electronic apparatus and includes a plurality of communication contacts that includes a first contact, to execute the control method according to claim 23 .
25. A control method of an electronic apparatus that is attachable to and detachable from an accessory and includes a plurality of communication contacts that includes a first contact, the control method comprising the steps of:
in a case where a signal level of the first contact is changed from a first signal level to a second signal level different from the first signal level in response to a start of a power supply, performing a predetermined communication different from a communication performed in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply;
wherein in a case where the signal level of the first contact is changed from the first signal level to the second signal level in response to a factor different from the start of the power supply, performing communication with the accessory using information indicating a communication factor,
wherein in a case where the signal level of the first contact is changed from the second signal level to the first signal level in response to a factor different from the start of the power supply, not performing communication with the accessory using information indicating a communication factor.
26. A non-transitory computer-readable storage medium storing a program that causes a computer of an electronic apparatus that is attachable to and detachable from an accessory and includes a plurality of communication contacts that includes a first contact, to execute the control method according to claim 25 .