Method and device for disabling a higher version of a computer bus and interconnection protocol for interoperability with a device compliant to a lower version of the computer bus and interconnection protocol

摘要

A method and a device for disabling a lower version of a computer bus and interconnection protocol (e.g., Peripheral Component Interconnect Express (PCIe) 2.0 or higher) for interoperability with a receiver compliant to a lower version of the protocol are disclosed. The device detects a presence of a receiver, and starts link training. During the link training, the number of link training failures or the elapsed time is counted. The device transmits a training sequence including symbols set in accordance with a higher version of the protocol that the device supports on each lane that the receiver is detected as long as the number of link training failures or the elapsed time is below a predetermined threshold. If the number of link training failures or the elapsed time reaches a predetermined threshold, the device transmits a training sequence including symbols set in accordance with a lower version of the protocol.