The GD25Q20B Serial flash supports the standard Serial Peripheral Interface (SPI), and a high performance Dual/Quad output as well as Dual/Quad SPI: Serial Clock, Chip Select, Serial Data I/O0 (SI), I/O1 (SO), I/O2 (WP#), and I/O3 (HOLD#). SPI clock frequencies of up to 120MHz are supported allowing equivalent clock rates of 240MHz for Dual Output & Dual I/O read command, and 480MHz for Quad output & Quad I/O read command.