The quad serial peripheral interface (QSPI) module is a kind of SPI module that allows single, dual, or quad read access to external SPI devices. This module has a memory mapped register interface, which provides a direct interface for accessing data from external SPI devices and thus simplifying software requirements. The QSPI works as a controller only. The QSPI in the device is primarily intended for fast booting from quad-SPI flash memories.

The QSPI supports the following features:

• Programmable clock divider
• Six-pin interface
• Programmable length (from 1 to 128 bits) of the words transferred
• Programmable number (from 1 to 4096) of the words transferred
• Support for 3-, 4-, or 6-pin SPI interface
• Optional interrupt generation on word or frame (number of words) completion
• Programmable delay between chip select activation and output data from 0 to 3 QSPI clock cycles

Timing Requirements for QSPI Input (Read) Timings and QSPI Switching Characteristics assume the operating conditions stated in QSPI Timing Conditions.