22.214.171.124. Characteristics of Signal Integrity Issues
The design may not always initialize and calibrate correctly, or may exhibit occasional bit errors in user mode. Severe signal integrity issues can result in total failure of an interface at certain data rates, and sporadic component failure because of electrical stress. PCB component variance and signal integrity issues often show up as failures on one PCB, but not on another identical board. Timing issues can have a similar characteristic. Multiple calibration windows or significant differences in the calibration results from one calibration to another can also indicate signal integrity issues.