The I/O interfacing options for the flash device are:
- A: Single 4-bit device on lower interface (a boot mode)
- B: Dual-stacked 4-bit on lower clocks and data (a boot mode)
- C: Dual-parallel 8-bit (a boot mode)
For boot modes, see Quad SPI Boot Mode.
Figure 1. QSPI I/O Interface Connection Diagrams