UMFT221XA-01, USB to 4-bit SPI/FT1248 Development Module for the FT221XQ Full Speed USB 2.0 Interface
Reference design by: FTDI Chip

UMFT221XA-01, USB to 4-bit SPI/FT1248 Development Module for the FT221XQ Full Speed USB 2.0 Interface

Other reference designs by FTDI Chip