GENERAL DESCRIPTION
   The GD25Q21B 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 104MHz are supported allowing equivalent clock rates of 208MHz for Dual Output & Dual I/O read command, and 416MHz for Quad output & Quad I/O read command.

FEATURES
♦ 2M-bit Serial Flash
   - 256K-byte
   - 256 bytes per programmable page
♦ Standard, Dual, Quad SPI
   - Standard SPI: SCLK, CS#, SI, SO, WP#, HOLD#
   - Dual SPI: SCLK, CS#, IO0, IO1, WP#, HOLD#
   - Quad SPI: SCLK, CS#, IO0, IO1, IO2, IO3
♦ High Speed Clock Frequency
   - 104MHz for fast read with 30PF load
   - Dual I/O Data transfer up to 208Mbits/s
   - Quad I/O Data transfer up to 416Mbits/s
♦ Software/Hardware Write Protection
   - Write protect all/portion of memory via software
   - Enable/Disable protection with WP# pin
   - Top or Bottom, Sector or Block selection
♦ Program/Erase Speed
   - Page Program time: 0.35ms typical
   - Sector Erase time: 50ms typical
   - Block Erase time: 0.18/0.25s typical
   - Chip Erase time: 0.8s typical
♦ Flexible Architecture
   - Sector of 4K-byte
   - Block of 32/64K-byte
♦ Low Power Consumption
   - 12mA maximum active current
   - 5μA maximum power down current
♦ Single Power Supply Voltage
   - Full voltage range: 2.7~3.6V
♦ Minimum 100,000 Program/Erase Cycles
♦ Advanced security Features
   - Power Supply Lock-Down
   - 3×512-Byte Security Registers With OTP Locks
   - Volatile and Non-volatile Status Register Bits