In the specification sheet, the “Flash” row says 2MB PSRAM, but first of all, is that Flash or PSRAM? Incidentally, the circuit diagram only shows P25Q16H (Flash Memory).
HI there,
So the data sheet shows this:
RP2350 is a new family of microcontrollers from Raspberry Pi that offers significant enhancements over RP2040. Key
features include:
• Dual Cortex-M33 or Hazard3 processors at 150 MHz
• 520 kB on-chip SRAM, in 10 independent banks
• 8 kB of one-time-programmable storage (OTP)
• Up to 16 MB of external QSPI flash/PSRAM via dedicated QSPI bus
◦
Additional 16 MB flash/PSRAM accessible via optional second chip-select
and
◦
RP2350 uses external flash
1.2.1.1. QFN-60 (RP2350A)
◦
RP2354 has 24 × 128 kB = 2 MB of internal flash
HTH
GL 
PJ 
I don’t think it’s a PSRAM , just a Flash. check the flash Data sheet. 
FYI, I f you need MORE flash then this D0 compatible additional Flash on the bottom of this board.
works very well also see the demo HERE