The Vivado IDE provides analysis of the switching noise levels associated with the I/O of different devices. SSN analysis provides estimates of the disruption that simultaneously switching outputs can cause on other output ports in the I/O bank. SSN analysis incorporates I/O bank-specific electrical characteristics into the prediction to better model package effects on SSN.
I/Os are grouped into separate isolated I/O banks, and each I/O bank has unique power distribution networks and unique responses to switching activity. Because power distribution networks within a packaged FPGA have different responses to noise, it is important to understand the I/O standards and number of I/Os in a design as well as the response of the device power system to this switching.
Xilinx characterizes all banks through three-dimensional extraction and simulation. This information is incorporated into SSN analysis. SSN analysis uses the expected switching profile of a device to predict how the switching affects the power network of the system and in turn, how other outputs in the I/O bank are affected.