Spartan UltraScale+ FPGAs do not support configuration from a single flash device that uses multiple chip select pins. For use with Spartan UltraScale+ FPGAs, these types of devices must offer a transparent interface and read behavior to the FPGA. Spartan UltraScale+ FPGAs also issue a single SPI read command to read in an entire PDI. If a flash does not read seamlessly with a single command across any die boundaries, it cannot be used to store a configuration PDI if the PDI crosses the die boundary.