WO-2025232588-A9 - APPARATUS, DEVICE AND SYSTEM FOR OPTICALLY TRANSMITTING PCIE SIDEBAND SIGNAL

WO2025232588A9WO 2025232588 A9WO2025232588 A9WO 2025232588A9WO-2025232588-A9

Abstract

Provided in the present disclosure are a transmission apparatus, transmission device and transmission system for optically transmitting a PCIe sideband signal. The transmission apparatus comprises a first sideband signal processing unit and a first sideband optical transceiving unit, wherein the first sideband signal processing unit is used for acquiring a first initial sideband electrical signal and converting the first initial sideband electrical signal into a first transmission sideband electrical signal; the first sideband optical transceiving unit is used for connecting to a first sideband optical channel that is independent of an in-band optical channel, and converting the first transmission sideband electrical signal into a first transmission sideband optical signal and sending same via the first sideband optical channel, and/or the first sideband optical transceiving unit is used for connecting to the first sideband optical channel that is independent of the in-band optical channel, receiving a second transmission sideband optical signal via the first sideband optical channel, and converting the second transmission sideband optical signal into a second transmission sideband electrical signal; and the first sideband signal processing unit is used for reconverting the received second transmission sideband electrical signal into a second initial sideband electrical signal.

Inventors

MENG, Huaiyu
SHEN, Yichen
WEHAGE, ERIC
HANEY, SPENCER
CHEN, QIAOWEN
SWARTZENTRUBER, RON

Assignees

上海曦智科技有限公司

Dates

Publication Date: 20260507
Application Date: 20250425
Priority Date: 20240506

Claims (20)

A transmission device for optically transmitting PCIe sideband signals, comprising: First sideband signal processing unit and first sideband optical transceiver unit; Wherein, the first sideband signal processing unit is used to acquire a first initial sideband electrical signal and convert the first initial sideband electrical signal into a first transmission sideband electrical signal; the first sideband optical transceiver unit is used to connect to a first sideband optical channel independent of the in-band optical channel and convert the first transmission sideband electrical signal into a first transmission sideband optical signal and transmit the first transmission sideband optical signal via the first sideband optical channel, and/or The first sideband optical transceiver unit is used to connect to a first sideband optical channel independent of the in-band optical channel and receive a second transmission sideband optical signal via the first sideband optical channel and convert the second transmission sideband optical signal into a second transmission sideband electrical signal. The first sideband signal processing unit is used to restore the received second transmission sideband electrical signal into a second initial sideband electrical signal.
According to claim 1, the transmission device, wherein, The first transmission sideband signal and the second transmission sideband signal are in UART format.
According to claim 2, the transmission device, wherein, The first initial sideband signal and the second initial sideband signal include an initial presence signal; The first transmission sideband signal and the second transmission sideband signal include a UART format presence signal; The first sideband signal processing unit, upon determining that the transmission device is connected to the PCIe terminal device, acquires the initial presence signal and converts the initial presence signal into a UART format presence signal for transmission by the first sideband optical transceiver unit; and When the first sideband signal processing unit determines that the transmission device is connected to the PCIe host device, it restores the UART format presence signal received by the first sideband signal optical transceiver unit to the initial presence signal.
The transmission device according to claim 3, wherein, The first sideband signal processing unit includes a plurality of presence signal pins, and determines that the transmission device is connected to a PCIe terminal device by detecting that the level of the plurality of presence signal pins drops to a first predetermined voltage range.
The transmission device according to claim 4, wherein, The first sideband signal processing unit further determines that the transmission device is connected to a PCIe host device by detecting that the level of at least one of the plurality of presence signal pins drops to a second predetermined voltage range, wherein the highest voltage of the second predetermined voltage range is lower than the lowest voltage of the first predetermined voltage range.
According to claim 1, the transmission device, wherein, The first sideband signal processing unit controls the first sideband optical transceiver unit to send the first transmission sideband optical signal at a predetermined time interval until an acknowledgment message for the first transmission sideband optical signal is received, or controls the first sideband optical transceiver unit to send the first transmission sideband optical signal a predetermined number of times.
According to claim 1, the transmission device, wherein, The first initial sideband signal and the second initial sideband signal also include an initial reset signal; The first transmission sideband signal and the second transmission sideband signal also include a UART format reset signal; Specifically, the first sideband signal processing unit acquires the initial reset signal upon determining that the transmission device is connected to the PCIe host device, and converts the initial reset signal into a UART format reset signal for the first sideband optical transceiver unit to perform electro-optical conversion before transmission; and When the first sideband signal processing unit determines that the transmission device is connected to the PCIe terminal device, it restores the UART format reset signal, which has been received and photoelectrically converted by the first sideband signal optical transceiver unit, into the initial reset signal.
The transmission device according to any one of claims 1-7, wherein, The first initial sideband signal and the second initial sideband signal also include the initial Internet Packet Explorer Ping message; The first and second transmission sideband signals also include Ping messages in UART format. The first sideband signal processing unit generates the initial Ping message in response to power-on, and converts the initial Ping message into a Ping message in UART format for the first sideband optical transceiver unit to perform electro-optical conversion and then transmit.
The transmission device according to claim 1 further includes: In-band optical transceiver unit, used to connect each optical channel in the in-band optical channels; and A receiver detection circuit is configured to perform receiver detection for each of the in-band optical channels to generate an initial receiver result electrical signal for each optical channel indicating whether the receiver detection for that optical channel was successful or failed. The first sideband signal processing unit also converts the initial receiver result electrical signal of each optical channel into a receiver detection result electrical signal in UART format. The first sideband optical transceiver unit also converts the UART format receiver detection result electrical signal into a UART format receiver detection result optical signal and transmits it via the first sideband optical channel.
According to claim 9, the transmission device, wherein the receiver detection circuit comprises: Multiple receiver detection sub-circuits, each of which is configured to perform receiver detection for a corresponding optical channel in the in-band optical channels, and Each receiver detection sub-circuit includes an RC circuit, and generates an initial receiver detection result electrical signal indicating successful receiver detection for the corresponding optical channel based on the time constant of the RC circuit responding to a common-mode voltage step being greater than a predetermined duration threshold, or generates an initial receiver detection result electrical signal indicating failed receiver detection for the corresponding optical channel based on the time constant being less than the predetermined duration threshold.
The transmission device according to claim 10, wherein each detection sub-circuit further comprises: The system consists of a first differential cable pair, a second differential cable pair, a detection unit, and two second resistors. The first differential cable pair is used to connect to the electro-optic converter in the in-band optical transceiver unit; The second differential cable pair is used to connect to the photoelectric converter in the in-band optical transceiver unit; The RC circuit includes two identical sub-RC circuits respectively coupled to the two cables of the first differential cable pair, each sub-RC circuit including a first capacitor and a first resistor. The detection unit is used to drive the common-mode voltage step on the first differential cable pair, determine the time constant of the two sub-RC circuits responding to the common-mode voltage step, and generate a receiver detection result electrical signal indicating successful receiver detection for the corresponding optical channel based on the time constant being greater than the predetermined duration threshold, or generate a receiver detection result electrical signal indicating failed receiver detection for the corresponding optical channel based on the time constant being less than the predetermined duration threshold; and The two second resistors are respectively coupled to the two cables of the second differential cable pair.
The transmission device according to claim 11, wherein the detection unit comprises: A common-mode voltage driving subunit is configured to drive a common-mode low voltage on the first differential cable pair to pull the voltage of the first capacitor down to a predetermined low voltage value, and after determining that the voltage across the first capacitor has been pulled down to the predetermined low voltage value, drive a common-mode high voltage on the first differential cable pair. A recording subunit records the time elapsed from the moment the common-mode voltage driving subunit drives the common-mode high voltage until the voltage across the first capacitor reaches a predetermined high voltage value, using this time constant as the time constant; and The determination unit generates an initial receiver detection result electrical signal indicating successful detection of the receiver in the corresponding optical channel based on the time constant being greater than the predetermined duration threshold, or generates an initial receiver detection result electrical signal indicating failed detection of the receiver in the corresponding optical channel based on the time constant being less than the predetermined duration threshold.
The transmission device according to claim 10, wherein, The first sideband signal processing unit also multiplexes and encodes the corresponding two or more initial reception detection result electrical signals of two or more optical channels among the multiple optical channels of the in-band optical channel into multiplexed reception detection result electrical signals in UART format. The first sideband optical transceiver unit also transmits the UART format multiplexed reception detection result electrical signal via the first sideband optical channel.
The transmission device according to claim 11, wherein, The detection unit is integrated into the first sideband signal processing unit.
The transmission device according to claim 11, wherein, The detection unit is implemented by a PCIe ReDriver chip.
A transmission device for optically transmitting a reference clock electrical signal, comprising: Second sideband signal processing unit, clock multiplexing unit, and second sideband optical transceiver unit The clock multiplexing unit includes a first branch and a second branch. Wherein, the second sideband signal processing unit enables the first tributary and disables the second tributary when it determines that the transmission device is connected to the PCIe host device, so that the clock multiplexing unit receives the reference clock electrical signal from the PCIe host device and sends the reference clock electrical signal to the second sideband optical transceiver unit via the first tributary. The second sideband optical transceiver unit then converts the reference clock electrical signal into a reference clock optical signal and transmits it. When the second sideband signal processing unit determines that the transmission device is connected to the PCIe terminal device, it enables the second branch and disables the first branch, so that the second sideband optical transceiver unit receives the reference clock optical signal and converts the reference clock optical signal into a reference clock electrical signal, and then the clock multiplexing unit sends the reference clock electrical signal to the PCIe terminal device via the second branch.
The transmission device according to claim 16, wherein, The clock multiplexing unit includes a clock selection unit, a first switch, and a second switch. The clock selection unit includes a first input/output terminal, an input terminal, and an output terminal; The first switch is connected between the output terminal and the second sideband optical transceiver unit, and together with the first input/output terminal and the output terminal, forms the first branch; The second switch is connected between the output terminal and the first input/output terminal, and together with the input terminal, the output terminal, and the first input/output terminal, forms the second branch. The second sideband signal processing unit, upon determining that the transmission device is connected to the PCIe host device, turns on the first switch and turns off the second switch to enable the first branch and disable the second branch. This allows the first input/output terminal to receive the reference clock electrical signal from the PCIe host device, and the reference clock electrical signal is transmitted sequentially via the output terminal and the first switch to the second sideband optical transceiver unit, where it is converted into a reference clock optical signal and transmitted. When the second sideband signal processing unit determines that the transmission device is connected to the PCIe terminal device, it turns on the second switch and turns off the first switch to enable the second branch and disable the first branch, so that the reference clock electrical signal obtained by the second sideband optical transceiver unit after converting the received reference clock optical signal is sent to the PCIe terminal device in sequence via the input terminal, the output terminal, the second switch and the first input/output terminal.
The transmission device according to claim 17, wherein, The output is also connected to a retimer for the in-band optical channel to transmit the reference clock signal to the retimer.
The transmission device according to claim 16, wherein, The second sideband signal processing unit includes a plurality of presence signal pins, and determines that the transmission device is connected to a PCIe terminal device by detecting that the level of at least one of the plurality of presence signal pins drops to a first predetermined voltage range.
The transmission device according to claim 19, wherein, The second sideband signal processing unit includes a plurality of presence signal pins, and determines that the transmission device is connected to a PCIe host device by detecting that the level of at least one of the plurality of presence signal pins drops to a second predetermined voltage range, wherein the highest voltage of the second predetermined voltage range is lower than the lowest voltage of the first predetermined voltage range.

Description

Devices, apparatus and systems for optically transmitting PCIe sideband signals This application claims priority to Chinese Patent Application No. 202410552032.6, filed on May 6, 2024, the disclosure of which is incorporated herein by reference in its entirety. Technical Field This disclosure relates to the field of optical signal communication, and more specifically to transmission apparatus, transmission devices and transmission systems for optically transmitting PCIe sideband signals. Background Technology As the data transmission rate supported by the PCIe (peripheral component interconnect express, high-speed serial computer expansion bus standard) protocol continues to increase, long-distance transmission via cables becomes difficult. Therefore, optical communication technology has been introduced into the PCIe field, with the aim of replacing electrical transmission with optical transmission. According to PCIe, in addition to high-speed data transmission within the band, some sideband signals also need to be transmitted at low speed outside the band (also known as sideband). These sideband signals are used to assist in controlling or managing data transmission within the band, and include, but are not limited to, the reset signal PERST, the presence signal PRSNT, the reference clock signal REFCLK, the SMbus signal, and optional signals such as WAKE, CLKREQ, PWRBRK, PWEREN, general I/O signals, and additional hot-plug signals. However, there are currently various challenges in transmitting these sideband signals, which are originally transmitted on sideband signal lines constructed by cables, over optical channels constructed by optical fibers. Therefore, it is necessary to propose a device capable of transmitting these sideband signals over optical channels. Summary of the Invention In view of the above, this disclosure provides a transmission apparatus, transmission device and transmission system for optically transmitting PCIe sideband signals, which enables the transmission of PCIe sideband signals over an optical channel constructed of optical fiber. According to a first aspect of this disclosure, a transmission apparatus for optically transmitting PCIe sideband signals is provided, comprising: a first sideband signal processing unit and a first sideband optical transceiver unit; wherein the first sideband signal processing unit is configured to acquire a first initial sideband electrical signal and convert the first initial sideband electrical signal into a first transmission sideband electrical signal, the first sideband optical transceiver unit is configured to connect to a first sideband optical channel independent of an in-band optical channel and convert the first transmission sideband electrical signal into a first transmission sideband optical signal and transmit the first transmission sideband optical signal via the first sideband optical channel, and/or the first sideband signal optical transceiver unit is configured to connect to a first sideband optical channel independent of an in-band optical channel and receive a second transmission sideband optical signal via the first sideband optical channel and convert the second transmission sideband optical signal into a second transmission sideband electrical signal, and the first sideband signal processing unit is configured to restore the received second transmission sideband electrical signal to a second initial sideband electrical signal. Optionally, the first transmission sideband signal and the second transmission sideband signal have UART format. Optionally, the first initial sideband electrical signal and the second initial sideband electrical signal include an initial presence signal; the first transmission sideband electrical signal and the second transmission sideband electrical signal include a UART-formatted presence signal; the first sideband signal processing unit acquires the initial presence signal when it determines that the transmission device is connected to a PCIe terminal device, and converts the initial presence signal into a UART-formatted presence signal for transmission by the first sideband optical transceiver unit; and the first sideband signal processing unit restores the UART-formatted presence signal received by the first sideband signal optical transceiver unit to the initial presence signal when it determines that the transmission device is connected to a PCIe host device. Optionally, the first sideband signal processing unit includes a plurality of presence signal pins, and determines that the transmission device is connected to a PCIe terminal device by detecting that the level of the plurality of presence signal pins drops to a first predetermined voltage range. Optionally, the first sideband signal processing unit further determines that the transmission device is connected to a PCIe host device by detecting that the level of at least one of the plurality of presence signal pins drops to a second predeter