Controlling electrical idle states in retimer outputs

Patent metadata

Field	Value
Publication number	US-12554670-B2
Application number	US-202318477470-A
Country	US
Kind code	B2
Filing date	Sep 28, 2023
Priority date	Sep 28, 2023
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

This application is directed to controlling an electrical idle state of a retimer of a data communication channel. A receiving side of the retimer obtains an input signal including at least an exit command and a data sequence following the exit command. The exit command requests the retimer to exit a target energy saving state and transmit the data sequence. The retimer splits the input signal into two distinct signals including a control signal carrying the exit command and a data signal carrying the data signal. The retimer extends the exit command carried by the control signal, outputs the control signal carrying the extended exit command at an output of the retimer, and in accordance with a determination that the retimer has been equalized and locked, outputs the data signal carrying the data sequence at the output of the retimer.

First claim

What is claimed is:

1 . A method for controlling an electrical idle state of a retimer, comprising:
obtaining, by a receiving side of the retimer, an input signal including at least an exit command and a data sequence following the exit command, the exit command requesting the retimer to exit a target energy saving state and transmit the data sequence; splitting the input signal into two distinct signals, the two distinct signals including a control signal carrying the exit command and a data signal carrying the data sequence; while training a core of the retimer and until the retimer is locked:
extending the exit command carried by the control signal; and
outputting the control signal carrying the extended exit command at an output of the retimer; and
in accordance with a determination that the retimer has been equalized and locked, outputting the data signal carrying the data sequence at the output of the retimer.

2 . The method of claim 1 , further comprising:
equalizing the retimer to compensate for distortion of the input signal and re-generate the data signal including the data sequence.

3 . The method of claim 2 , further comprising:
detecting a start of the data sequence in the input signal, wherein the retimer is equalized in response to detection of the start of the data sequence in the input signal.

4 . The method of claim 1 , further comprising:
in accordance with a determination that the retimer has been equalized and locked, terminating the extended exit command in the control signal; wherein the data sequence is outputted to the output of the retimer within a predefined electrical idle duration after the extended exit command is terminated.

5 . The method of claim 1 , wherein the exit command includes a digital signal having a first frequency, and the data sequence includes a plurality of data bits temporally encoded according to a clock signal having a second frequency that is greater than the first frequency.

6 . The method of claim 1 , wherein separating the input signal into the control signal and the data signal further includes extracting an envelope of the exit command, the method further comprising:
determining a burst width of the envelope of the exit command; and identifying the exit command based on the burst width of the envelope of the exit command.

7 . The method of claim 1 , wherein:
the exit command is extended in the control signal in accordance with a determination that the exit command satisfies an exit condition requiring that the exit command is (i) followed by the data sequence within a predefined short duration and (ii) has a burst width that is greater than a predefined burst value.

8 . The method of claim 1 , wherein:
the retimer has a plurality of energy saving states, each of which corresponds to a respective one of a plurality of burst width ranges associated with a burst width of the exit command; a first burst width range includes a burst width greater than the ping value, and corresponds to exiting of a first energy saving state (U 1 ); a second burst width range includes a burst width greater than a polling value, and corresponds to exiting of a second energy saving state (U 2 ) or wakeup of a third energy saving state (U 3 ); and the exit condition requires at least that the exit command corresponds to exiting the first energy saving state (U 1 ), the second energy saving state (U 2 ), or the third energy saving state (U 3 ).

9 . The method of claim 1 , further comprising:
determining a burst width of the exit command; in accordance with a determination that the burst width of the exit command falls within a target burst width range corresponding to exiting of the target energy saving state, determining that the retimer is requested by the exit command to exit the target energy saving state.

10 . The method of claim 9 , further comprising:
recognizing, in the control signal, a state indicating message based on a burst width of the state indicating message, the state indicating message indicating the retimer operates in the target energy saving state; and wherein, in accordance with a determination that the exit command follows the state indicating message, it is determined that the retimer is requested by the exit command to exit the target energy saving state; wherein a first ping range corresponds to the state indicating message of a first energy saving state (U 1 ), and includes any burst width less than a ping value.

11 . The method of claim 1 , wherein the retimer has a plurality of energy saving states, each of which corresponds to a respective one of a plurality of burst width ranges, the method further comprising:
in accordance with a determination that a burst width of the exit command falls within a target burst width range of the plurality of burst width ranges, determining that the retimer is requested by the exit command to exit the target energy saving state, among the plurality of energy saving states, the target energy saving state corresponding to the target burst width range.

12 . The method of claim 11 , wherein:
the first burst width range corresponds to exiting of a first energy saving state (U 1 ), and includes a burst width greater than the ping value; and a second burst width range includes a burst width above a polling value, and corresponds to exiting of a second energy saving state (U 2 ) or wakeup of a third energy saving state (U 3 ).

13 . The method of claim 1 , the method further comprising:
in accordance with a determination that there is no data sequence on the input signal for an extended duration of time and the exit command of the input signal has a burst width greater than a predefined ping value that defines exiting of the target energy saving state, determining that the retimer is requested by the exit command to operate at one of an LFPS-based pulse width (LBPW) state and a polling state, and aborting extending the exit command in the control signal.

14 . A retimer device, comprising:
an input interface for obtaining, by a receiving side of the retimer device, an input signal including at least an exit command and a data sequence following the exit command, the exit command requesting the retimer device to exit a target energy saving state to transmit the data sequence in a normal state; a low frequency periodic signaling (LFPS) module coupled to the input interface, the LFPS module configured to extract, from the input signal, a control signal carrying the exit command and extend the exit command in the control signal; a retimer core coupled to the input interface, the retimer core configured to re-generate a data signal carrying the data sequence from the input signal; and a multiplexer coupled to the LFPS module and the retimer core, wherein the multiplexer is configured to:
select the control signal and output the control signal carrying the extended exit command at an output of the retimer device; and
in accordance with a determination that the retimer device has been equalized and locked, select the data signal and output the data signal carrying the data sequence at the output of the retimer device;
wherein while the retimer core is being trained and until the retimer core is locked, retimer device extends the exit command carried by the control signal and outputs the control signal carrying the extended exit command.

15 . The retimer device of claim 14 , further comprising:
a high speed detector coupled to the retimer core and configured to detect a start of the data sequence in the input signal.

16 . The retimer device

Assignees

• Parade Tech Ltd

Inventors

• Wang Hongquan
• Xu Liang
• Xu Feng
• Chen Yuanping
• Gao Mengchuan

Classifications

• G06F1/3253 Primary

  Power saving in bus · CPC title

• G06F2213/0026

  PCI express · CPC title

• G06F2213/0042

  Universal serial bus [USB] · CPC title

• G06F13/4282 Primary

  on a serial bus, e.g. I2C bus, SPI bus (on daisy chain buses G06F13/4247) · CPC title