High Speed Interface

In digital communication, data is represented as a binary bitstream of 0s and 1s. In practice, real-world data is rarely truly random — it often contains repetitive patterns, especially long runs of identical bits (e.g., ...000000... or ...111111...). At low speeds this causes no real harm, but at 1 Gbps and beyond, such patterns create critical signal integrity problems. At 1 Gbps, one bit period is just 1 nanosecond, so a run of tens or hundreds of identical bits means the signal voltage stays constant for a relatively long time. ...

What is Skew? Skew refers to the timing difference in signal arrival between multiple paths that are supposed to be synchronized. shows a skewed waveform between data lines. Why Skew Simulation Is Necessary If you simulate your design assuming everything is perfectly aligned, you may encounter issues during actual testing. In real PCBs, skew naturally exists, which is why techniques like length matching are necessary. However, even with length matching, the impact of skew becomes more significant as signal speed increases. Therefore, it’s important to address skew issues during simulation. ...