The QSPI flash devices have the following advantages:
- Reliability: they typically support a minimum of 100,000 erase cycles per sector and a minimum of 20 years data retention. As a result, their management is simpler, with no need for error correction and bad block management.
- Low pin count requirement: a quad SPI flash device typically requires six pins, but it can be used with as few as four pins.
- High bandwidth
A quad SPI flash device typically has smaller storage capacity than other flash devices. They are therefore mostly used as a boot source and not for mass storage.
Up to four quad SPI flash chip selects can be used with Intel Stratix 10 devices. The FPGA will configure only from quad SPI flash connected to the chip select zero, while the others may be used for mass storage purposes.
The standard for QSPI flash devices has a lot of variability, and the QSPI flash controller has some limitations. Therefore there is a need for each family of flash devices to be tested and validated individually to confirm compatibility with Intel Stratix 10.