AR# 69889

描述

When the Classification feature is enabled in UltraScale+ devices, timing can fail on the SPI flash pins (spi_c, spi_d, spi_q, and spi_s_n).  

The errors are similar to the following:

CRITICAL WARNING: [Timing 38-282] Negative MIN PERIOD slack violation

CRITICAL WARNING: [Timing 38-282] Negative SETUP slack violation

解决方案

When selecting I/O pins for the SPI flash interface, ensure that these I/O pins are placed in the I/O bank closest to the SEM controller to ensure timing closure.