Repeater, cable, and control method

1 . A repeater connected to a communication channel that communicably connects two apparatuses, the repeater comprising:

a corrector that corrects a signal that travels through the communication channel;

memory that is non-volatile writable memory and stores a parameter pertaining to an operation of the corrector; and

a controller that uses the parameter stored in the memory to control an operation of the repeater,

wherein the controller:

receives a control message from at least one apparatus out of the two apparatuses;

stores, in the memory, a parameter included in the control message received; and

uses the parameter stored in the memory to control the operation of the repeater.

2 . The repeater according to claim 1 , wherein

the communication channel includes a first line for data communication between the two apparatuses and a second line for communication for configuration of the two apparatuses which is different from the first line,

the corrector corrects a signal that travels through the first line, and

the controller receives the control message via the second line.

3 . The repeater according to claim 1 , wherein

the controller receives the control message from the at least one apparatus out of the two apparatuses, and causes a transition from one of (i) a prohibition mode and (ii) a permission mode to an other of the prohibition mode and the permission mode, the prohibition mode being a mode in which rewriting to the memory is prohibited, the permission mode being a mode in which rewriting to the memory is permitted.

4 . The repeater according to claim 1 , wherein

the controller receives the control message from the at least one apparatus out of the two apparatuses, and stores, in the memory, an identifier included in the control message as a first identifier that is an identifier of the repeater.

5 . The repeater according to claim 4 , wherein

the controller:

among one or more messages received by the at least one apparatus out of the two apparatuses, receives a message including the first identifier and a message including a second identifier that is an identifier to control the repeater as control messages each of which is the control message directed to the repeater; and

among the one or more messages, prohibits receiving a message including neither the first identifier nor the second identifier.

6 . The repeater according to claim 1 , wherein

the control message includes a parameter to be stored in the memory and an address at which the parameter is to be written, and

the controller stores the parameter at the address.

7 . The repeater according to claim 1 , wherein

the memory is one time programmable (OTP) memory.

8 . The repeater according to claim 7 , wherein

the memory includes a plurality of storage areas, and for each of the plurality of storage areas, a parameter comprising one or more parameters each of which is the parameter can be stored only once, and

the controller:

when a new parameter comprising one or more parameters each of which is the parameter to be stored in the memory is stored in the memory, stores the new parameter in a storage area in which no parameter has yet been stored, the storage area being among the plurality of storage areas; and

when a parameter is read from the memory, reads, from a storage area in which a parameter has been stored most recently, the parameter stored, the storage area being among the plurality of storage areas.

9 . The repeater according to claim 1 , wherein

the corrector includes a retimer or a redriver, and

the memory stores the parameter pertaining to an operation of the retimer or an operation of the redriver.

10 . The repeater according to claim 1 , wherein

among communication channels that conform to a USB standard, the communication channel is a data line for data communication between the two apparatuses,

the controller receives the control message from either of the two apparatuses via a configuration channel (CC) line for communication for configuration of the two apparatuses, the CC line being among the communication channels that conform to the USB standard, and

the memory stores a parameter to be referred to by eMarker or a parameter to be referred to by the corrector.

11 . A cable comprising:

a plug portion that includes the repeater according to claim 1 .

12 . A repeater connected to a communication channel that communicably connects two apparatuses, the repeater comprising:

a corrector that corrects a signal that travels through the communication channel;

memory that is non-volatile writable memory and stores a parameter pertaining to an operation of the corrector; and

a controller that uses the parameter stored in the memory to control an operation of the repeater,

wherein:

the corrector has an operation mode that conforms to at least one communication standard out of USB 4.0, USB 3.2, Thunderbolt (registered trademark) 3, DisplayPort Alt Mode, or HDMI (registered trademark) Alt Mode, and

the memory stores the parameter for correcting the signal that conforms to the at least one communication standard.

13 . A cable comprising:

a first plug portion that includes a first repeater; and

a second plug portion that includes a second repeater, wherein

the first repeater:

is connected to a first communication channel that communicably connects two apparatuses; and

includes:

a first corrector that corrects a signal that travels through the first communication channel;

first memory that is non-volatile writable memory and stores a first parameter pertaining to an operation of the first corrector; and

a first controller that uses the first parameter stored in the first memory to control an operation of the first repeater,

the second repeater:

is connected to a second communication channel that communicably connects the two apparatuses; and

includes:

a second corrector that corrects a signal that travels through the second communication channel;

second memory that is non-volatile writable memory and stores a second parameter pertaining to an operation of the second corrector; and

a second controller that uses the second parameter stored in the second memory to control an operation of the second repeater,

the first repeater and the second repeater are connected to a single communication channel composed of the first communication channel and the second communication channel, and

an identifier of the first repeater which is stored in the first memory of the first repeater is different from an identifier of the second repeater which is stored in the second memory of the second repeater.

14 . A control method of controlling a repeater connected to a communication channel that communicably connects two apparatuses, wherein

the repeater includes:

a corrector that corrects a signal that travels through the communication channel; and

memory that is non-volatile writable memory and stores a parameter pertaining to an operation of the repeater, and

the control method comprises:

correcting, by the corrector, the signal that travels through the communication channel;

receiving a control message from at least one apparatus out of the two apparatuses;

storing, in the memory, the parameter which is included in the control message received;

using the parameter stored in the memory to control the operation of the repeater.