M25PX32 Datasheet - STMicroelectronics

The M25PX32 is a 32 Mbit (4 Mb x 8) serial Flash memory, with advanced write protection mechanisms, accessed by a high speed SPI-compatible bus.
The M25PX32 supports two new, high-performance dual input/output instructions:

1. Dual Output Fast Read (DOFR) instruction used to read data at up to 75 MHz by using
both pin DQ1 and pin DQ0 as outputs

2. Dual Input Fast Program (DIFP) instruction used to program data at up to 75 MHz by
using both pin DQ1 and pin DQ0 as inputs