Signal transmission method and system and retimer

1. A retimer for link equalization, comprising:

a data channel circuit configured to implement, under a function of a current phase locked loop, equalization processing-based transparent transmission of a signal between a first communications device and a second communications device;

a link adjustment circuit configured to:

obtain the signal transmitted in the data channel circuit;

obtain link status information based on the obtained signal;

in response to determining, based on the link status information, that a rate of a link needs to be changed, configure in advance an operating parameter of a target phase locked loop as an operating parameter corresponding to a changed rate, wherein the target phase locked loop is an unused phase locked loop in at least two phase locked loops; and

switch the current phase locked loop to the target phase locked loop in response to detecting that the link enters a rate-changing state,

wherein the data channel circuit is further configured to implement, under a function of the target phase locked loop, the equalization processing-based transparent transmission of the signal between the first communications device and the second communications device,

wherein the link adjustment circuit is further configured to:

perform equalization adjustment in response to determining, based on the link status information, that the link is in an equalized state, and

determine a target equalization parameter value in response to detecting that the link enters the rate-changing state, wherein the target equalization parameter value is an equalization parameter value corresponding to the changed rate, and the target equalization parameter value is correlated with the changed rate.

2. The retimer according to claim 1 , wherein the data channel circuit comprises a clock and data recovery circuit, an output buffer, and an equalization circuit; and

the link adjustment circuit is configured to perform equalization adjustment on the equalization circuit in response to determining, based on the link status information, that the link is in the equalized state.

3. The retimer according to claim 1 , wherein the correlated with the changed rate is a positive correlation.

4. The retimer according to claim 1 , wherein the link adjustment circuit is further configured to configure the data channel circuit in response to detecting that the first communications device is connected to the retimer and the second communications device is connected to the retimer, so that the following situations (a), (b) and (c) occur:

(a) a first negotiation signal from the first communications device can be transmitted to the second communications device in a transparent transmission manner,

(b) a second negotiation signal from the second communications device can be transmitted to the first communications device in the transparent transmission manner, and

(c) the first communications device and the second communications device complete a negotiation procedure by using the first negotiation signal and the second negotiation signal.

5. The retimer according to claim 1 , wherein the link adjustment circuit comprises a link status circuit and a phase locked loop control circuit, wherein:

the link status circuit is configured to obtain a signal transmitted in the data channel circuit; obtain link status information based on the obtained signal; determine, based on the link status information, that a rate of a link needs to be changed;

the phase locked loop control circuit is configured to: in response to the link status circuit determining that the rate of the link needs to be changed, configure an operating parameter of a target phase locked loop as an operating parameter corresponding to a changed rate, wherein the target phase locked loop is an unused phase locked loop in the at least two phase locked loops;

the link status circuit is further configured to detect that the link enters a rate-changing state; and

the phase locked loop control circuit is further configured to switch a currently used phase locked loop to the target phase locked loop in response to the link status circuit detecting that the link enters the rate-changing state.

6. The retimer according to claim 5 , wherein the link adjustment circuit further comprises a link equalization control circuit;

the link status circuit is further configured to determine, based on the link status information, that the link is in an equalized state; and

the link equalization control circuit is configured to control the link to perform equalization adjustment in response to the link status circuit determining that the link is in the equalized state.

7. The retimer according to claim 6 , wherein the link equalization control circuit is further configured to determine a target equalization parameter value in response to the link status circuit detecting that the link enters the rate-changing state, wherein the target equalization parameter value is an equalization parameter value corresponding to the changed rate, and the target equalization parameter value is positively correlated with the changed rate.

8. The retimer according to claim 5 , wherein the link status circuit is further configured to configure the data channel circuit in response to detecting that the first communications device is connected to the data channel circuit and the second communications device is connected to the data channel circuit, so that the following situations (a), (b) and (c) occur:

(a) a first negotiation signal from the first communications device can be transmitted to the second communications device in the transparent transmission manner,

(b) a second negotiation signal from the second communications device can be transmitted to the first communications device in a transparent transmission manner, and

(c) the first communications device and the second communications device complete a negotiation procedure by using the first negotiation signal and the second negotiation signal.

9. A signal transmission method, wherein the method is performed by a retimer for link equalization, and the method comprises:

implementing, by a data channel circuit of the retimer, equalization processing-based transparent transmission of a signal between a first communications device and a second communications device;

obtaining, by a link adjustment circuit of the retimer, the transmitted signal;

obtaining, by the link adjustment circuit of the retimer, link status information based on the obtained signal;

in response to determining, based on the link status information, that a rate of a link needs to be changed, configuring in advance, by the link adjustment circuit of the retimer, an operating parameter of a target phase locked loop as an operating parameter corresponding to a changed rate, wherein the target phase locked loop is an unused phase locked loop in at least two phase locked loops;

switching, by the link adjustment circuit of the retimer, a currently used phase locked loop to the target phase locked loop in response to detecting that the link enters a rate-changing state; and

implementing, by the data channel circuit of the retimer, under a function of the target phase locked loop, the equalization processing-based transparent transmission of the signal between the first communications device and the second communications device,

wherein the method further comprises:

performing, by the link adjustment circuit, equalization adjustment in response to determining, based on the link status information, that the link is in an equalized state, and

determining, by the link adjustment circuit of the retimer, a target equalization parameter value in response to detecting that the link enters the rate-changing state, wherein the target equalization parameter value is an equalization parameter value corresponding to the changed rate, and the target equalization parameter value is correlated with the changed rate.

10. The method according to claim 9 , wherein the correlated with the changed rate is a positive correlation.

11. The method according to claim 9 , wherein the method further comprises: configuring, by the link adjustment circuit of the retimer, the data channel circuit of the retimer in response to detecting that the first communications device is connected to the retimer and the second communications device is connected to the retimer, so that the following situations (a), (b) and (c) occur:

(a) a first negotiation signal from the first communications device can be transmitted to the second communications device in the transparent transmission manner,

(b) a second negotiation signal from the second communications device can be transmitted to the first communications device in a transparent transmission manner, and

(c) the first communications device and the second communications device complete a negotiation procedure by using the first negotiation signal and the second negotiation signal.

12. A signal transmission system, wherein the system comprises a first communications device, a second communications device, and at least one retimer for link equalization, wherein:

the first communications device is configured to send a first signal to the at least one retimer;

the at least one retimer is configured to transmit the first signal to the second communications device in a transparent transmission manner;

the second communications device is configured to send a second signal to the at least one retimer; and

the at least one retimer is further configured to transmit the second signal to the first communications device in the transparent transmission manner; and

the at least one retimer comprises a data channel circuit, a link adjustment circuit, and at least two phase locked loops, wherein:

the data channel circuit is configured to implement, under a function of a current phase locked loop, equalization processing-based transparent transmission of a signal between the first communications device and the second communications device;

the link adjustment circuit is configured to:

obtain the signal transmitted in the data channel circuit;

obtain link status information based on the obtained signal;

in response to determining, based on the link status information, that a rate of a link needs to be changed, configure in advance an operating parameter of a target phase locked loop as an operating parameter corresponding to a changed rate, wherein the target phase locked loop is an unused phase locked loop in the at least two phase locked loops;

switch the current phase locked loop to the target phase locked loop when detecting that the link enters a rate-changing state; and

the data channel circuit is further configured to implement, under a function of the target phase locked loop, the equalization processing-based transparent transmission of the signal between the first communications device and the second communications device,

wherein the link adjustment circuit of the retimer is further configured to perform equalization adjustment in response to determining, based on the link status information, that the link is in an equalized state, and

wherein the link adjustment circuit of the retimer is further configured to determine a target equalization parameter value in response to detecting that the link enters the rate-changing state, wherein the target equalization parameter value is an equalization parameter value corresponding to the changed rate, and the target equalization parameter value is correlated with the changed rate.

13. The signal transmission system according to claim 12 , wherein the data channel circuit of the retimer comprises a clock and data recovery circuit, an output buffer, and an equalization circuit; and

the link adjustment circuit of the retimer is configured to perform equalization adjustment on the equalization circuit in response to determining, based on the link status information, that the link is in the equalized state.

14. The signal transmission system according to claim 12 , wherein the correlated with the changed rate is a positive correlation.

15. The signal transmission system according to claim 12 , wherein the link adjustment circuit of the retimer is further configured to configure the data channel circuit in response to detecting that the first communications device is connected to the retimer and the second communications device is connected to the retimer, so that the following situations (a), (b) and (c) occur:

(a) a first negotiation signal from the first communications device can be transmitted to the second communications device in a transparent transmission manner,

(b) a second negotiation signal from the second communications device can be transmitted to the first communications device in the transparent transmission manner, and

(c) the first communications device and the second communications device complete a negotiation procedure by using the first negotiation signal and the second negotiation signal.

16. The signal transmission system according to claim 12 , wherein the link adjustment circuit of the retimer comprises a link status circuit and a phase locked loop control circuit, wherein:

the link status circuit is configured to obtain a signal transmitted in the data channel circuit; obtain link status information based on the obtained signal; determine, based on the link status information, that a rate of a link needs to be changed; and

the phase locked loop control circuit is configured to: in response to the link status circuit determining that the rate of the link needs to be changed, configure an operating parameter of a target phase locked loop as an operating parameter corresponding to a changed rate, wherein the target phase locked loop is an unused phase locked loop in the at least two phase locked loops;

the link status circuit is further configured to detect that the link enters a rate-changing state; and

the phase locked loop control circuit is further configured to switch a currently used phase locked loop to the target phase locked loop in response to the link status circuit detecting that the link enters the rate-changing state.

17. The signal transmission system according to claim 16 , wherein the link adjustment circuit of the retimer further comprises a link equalization control circuit;

the link status circuit is further configured to determine, based on the link status information, that the link is in an equalized state; and

the link equalization control circuit is configured to control the link to perform equalization adjustment in response to the link status circuit determining that the link is in the equalized state.