# US 12,117,955 B2 · Spread spectrum clock negotiation method, and peripheral component interconnect express device and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,117,955 B2 - Document ID: US12117955B2 - Status: Granted - Kind: B2 - Application number: 17/951,473 - Filed: 2022-09-23 - Published: 2024-03-28 - Granted: 2024-10-15 - Earliest claimed: 2020-03-24 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Er Nie; Kun Wang; Pan Li - Web page: https://patentgrep.com/patent/US12117955B2 ## CPC - G06F 13/423: {with synchronous protocol} - G06F 13/4282: {on a serial bus, e.g. I2C bus, SPI bus (on daisy chain buses G06F13/4247)} - G06F 1/04: Generating or distributing clock signals or signals derived directly therefrom - G06F 1/08: Clock generators with changeable or programmable clock frequency - G06F 1/12: Synchronisation of different clock signals {provided by a plurality of clock generators} - G06F 13/1689: {Synchronisation and timing concerns (synchronisation on a memory bus G06F13/4234)} - G06F 13/405: {where the bridge performs a synchronising function} - G06F 13/4072: {Drivers or receivers (G06F13/4086 takes precedence; for multistate logic circuits H03K19/0002)} - G06F 13/4291: {using a clocked protocol} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract This application provides a spread spectrum clock negotiation method, and a peripheral component interconnect express device and system, to implement dynamic negotiation between a transmit end and a receive end on an SSC capability in the peripheral component interconnect express system. The method includes: A second PCIe device generates first indication information, where the first indication information is used to indicate whether the second PCIe device has a spread spectrum clock capability. The second PCIe device sends the first indication information to a first PCIe device. The first PCIe device determines, based on the first indication information, whether to perform spread spectrum clock on a reference clock of the first PCIe device. ## Claims ### Claim 1 A spread spectrum clock negotiation method, comprising: receiving, by a first peripheral component interconnect express (PCIe) device from a second PCIe device, first indication information indicating whether the second PCIe device has a spread spectrum clock capability, wherein the receiving, by the first PCIe device from the second PCIe device, first indication information comprises: receiving, by the first PCIe device from the second PCIe device, a first skip (SKP) ordered set carrying the first indication information; and parsing, by the first PCIe device, the first SKP ordered set to obtain the first indication information; and determining, by the first PCIe device based on the first indication information, whether to perform spread spectrum clock on a reference clock of the first PCIe device. ### Claim 2 (depends on 1) The method according to claim 1, wherein the determining, by the first PCIe device based on the first indication information, whether to perform spread spectrum clock on a reference clock of the first PCIe device comprises: performing, by the first PCIe device, spread spectrum clock on the reference clock in response to that the first indication information indicates that the second PCIe device has the spread spectrum clock capability. ### Claim 3 (depends on 2) The method according to claim 2, wherein after the performing, by the first PCIe device, spread spectrum clock on the reference clock, the method further comprises: sending, by the first PCIe device to the second PCIe device, data based on the reference clock obtained after the spread spectrum clock. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: receiving, by the first PCIe device from the second PCIe device, second indication information indicating whether the second PCIe device supports transmission/reception of an SKP ordered set at a specified rate less than a preset rate. ### Claim 5 (depends on 4) The method according to claim 4, wherein after the receiving, by the first PCIe device from the second PCIe device, second indication information, the method further comprises: periodically sending, by the first PCIe device to the second PCIe device, a second SKP ordered set at the specified rate in response to that the second indication information indicates that the second PCIe device supports transmission/reception of the SKP ordered set at the specified rate. ### Claim 6 (depends on 4) The method according to claim 4, wherein the receiving, by the first PCIe device from the second PCIe device, second indication information comprises: receiving, by the first PCIe device from the second PCIe device, the first SKP ordered set sent carrying the second indication information; and parsing, by the first PCIe device, the first SKP ordered set to obtain the second indication information. ### Claim 7 A peripheral component interconnect express (PCIe) device, comprising: a receiver, configured to receive, from a second PCIe device, first indication information indicating whether the second PCIe device has a spread spectrum clock capability; and a processor, configured to determine, based on the first indication information, whether to perform spread spectrum clock on a reference clock of the PCIe device, wherein when receiving, from the second PCIe device, the first indication information, the receiver is configured to: receive, from the second PCIe device, a first skip (SKP) ordered set carrying the first indication information; and the processor is further configured to: parse the first SKP ordered set to obtain the first indication information. ### Claim 8 (depends on 7) The device according to claim 7, wherein when determining, based on the first indication information, whether to perform spread spectrum clock on the reference clock of the PCIe device, the processor is configured to: perform spread spectrum clock on the reference clock in response to that the first indication information indicates that the second PCIe device has the spread spectrum clock capability. ### Claim 9 (depends on 8) The device according to claim 8, further comprising: a transmitter, configured to: after the processor performs spread spectrum clock on the reference clock, send, to the second PCIe device, data based on the reference clock obtained after the spread spectrum clock. ### Claim 10 (depends on 7) The device according to claim 7, wherein the receiver is further configured to: receive, from the second PCIe device, second indication information indicating whether the second PCIe device supports transmission/reception of an SKP ordered set at a specified rate less than a preset rate. ### Claim 11 (depends on 10) The device according to claim 10, further comprising: a transmitter, configured to: after the receiver receives the second indication information, periodically send a second SKP ordered set to the second PCIe device at the specified rate in response to that the second indication information indicates that the second PCIe device supports transmission/reception of the SKP ordered set at the specified rate. ### Claim 12 (depends on 10) The device according to claim 10, wherein when receiving, from the second PCIe device, the second indication information, the receiver is configured to: receive, from a second PCIe device, the first SKP ordered set carrying the second indication information; and the processor is further configured to: parse the first SKP ordered set to obtain the second indication information. ### Claim 13 A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor, cause the processor to: receive, from a second peripheral component interconnect express (PCIe) device, first indication information indicating whether the second PCIe device has a spread spectrum clock capability, wherein when receiving, from the second PCIe device, the first indication information, the processor is caused to: receive, from the second PCIe device, a first skip (SKP) ordered set carrying the first indication information; and parse the first SKP ordered set to obtain the first indication information; and determine, based on the first indication information, whether to perform spread spectrum clock on a reference clock of the first PCIe device. ### Claim 14 (depends on 13) The non-transitory machine-readable medium of claim 13, the processor is further to perform spread spectrum clock on the reference clock in response to that the first indication information indicates that the second PCIe device has the spread spectrum clock capability. ### Claim 15 (depends on 13) The non-transitory machine-readable medium of claim 13, the processor is further to: sending, to the second PCIe device, data based on the reference clock obtained after the spread spectrum clock. ### Claim 16 (depends on 13) The non-transitory machine-readable medium of claim 13, the processor is further to: receive, from the second PCIe device, second indication information indicating whether the second PCIe device supports transmission/reception of an SKP ordered set at a specified rate less than a preset rate. ### Claim 17 (depends on 16) The non-transitory machine-readable medium of claim 16, the processor is further to: periodically send, to the second PCIe device, a second SKP ordered set at the specified rate in response to that the second indication information indicates that the second PCIe device supports transmission/reception of the SKP ordered set at the specified rate.