====== QSPI ======

Quad SPI is similar to SPI, but it has two additional data lines.

===== Protocol =====

==== Flash commands ====

=== WRITE_STATUS (0x01) ===
=== PAGE_PROGRAM (0x02) ===  
=== READ_DATA (0x03) ===  
=== WRITE_DISABLE (0x04) ===
=== READ_STATUS (0x05) ===  
=== WRITE_ENABLE (0x06) ===  
=== FAST_READ (0x0B) ===
=== WRITE_STATUS_3 (0x11) ===
=== READ_STATUS_3 (0x15) ===
=== SECTOR_ERASE (0x20) ===  
=== WRITE_STATUS_2 (0x31) ===
=== QUAD_INPUT_PAGE_PROGRAM (0x32) ===
=== READ_STATUS_2 (0x35) ===
=== INDIVIDUAL_BLOCK_LOCK (0x36) ===
=== INDIVIDUAL_BLOCK_UNLOCK (0x39) ===
=== FAST_READ_DUAL_OUTPUT (0x3B) ===
Dual SPI
=== READ_BLOCK_LOCK (0x3D) ===
=== PROGRAM_SECURITY (0x42) ===
=== ERASE_SECURITY (0x44) ===
=== READ_SECURITY (0x48) ===
=== READ_UNIQUE_ID (0x4B) ===
=== VOLATILE_SR_WRITE_ENABLE (0x50) ===
=== BLOCK_ERASE_32KB (0x52) ===
=== READ_SFDP (0x5a) ===  
=== CHIP_ERASE_A (0x60) ===
=== ENABLE_RESET (0x66) ===
=== FAST_READ_QUAD_OUTPUT (0x6B) ===
Quad SPI
=== ERASE_PROGRAM_SUSPEND (0x75) ===
=== SET_BURST_WITH_WRAP (0x77) ===
=== ERASE_PROGRAM_RESUME (0x7A) ===
=== GLOBAL_BLOCK_LOCK (0x7E) ===
=== MANUFACTURER_DEVICE_ID (0x90) ===
=== MFTR_DEVICE_ID_DUAL_IO (0x92) ===
Dual SPI
=== MFTR_DEVICE_ID_QUAD_IO (0x94) ===
Quad SPI
=== GLOBAL_BLOCK_UNLOCK (0x98) ===
=== RESET_DEVICE (0x99) ===
=== READ_JEDEC_ID (0x9f) === 
=== RELEASE_POWER_DOWN_ID (0xAB) ===
=== POWER_DOWN (0xB9) ===
=== FAST_READ_DUAL_IO (0xBB) ===
Dual SPI
=== CHIP_ERASE (0xC7) ===
=== BLOCK_ERASE_64KB (0xD8) ===
=== FAST_READ_QUAD_IO (0xEB) ===
Quad SPI