Using QSPI for in-package PSRAM (IDFGH-12497)

[hopkinskong]

Answers checklist.

• [X] I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• [X] I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• [X] I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

Hi,

I am currently using ESP32-S3R8V which contains an in-package 8MB Octal SPI PSRAM. Since I wish to free up 4 GPIOs for other uses, is it possible to drive the in-package PSRAM with QSPI mode? (My Flash is also in QSPI mode.)

If it is not possible in the boot stage / bootloader, can I do that in application after my ESP32S3 has boot up?

Thanks.

[andylinpersonal]

S3R8(V) and S3R16V’s in-package PSRAM chips from AP Memory don’t support any IO mode narrower than OPI at all. Details are in AP Memory’s datasheets. If you really want to free up these four pins, you can use ESP32-S3R2 with a smaller 2MB QSPI PSRAM, or connect S3 to your own external ESP or AP Memory’s QSPI PSRAM chip instead.

[hopkinskong]

Thanks. How about using the PSRAM as a temporary storage only? For example, I will fill the internal RAM first, then dump the data onto the PSRAM, then I disable the PSRAM via some ESP-IDF API (or making sure the PSRAM's CS will never go LOW), then fill the internal RAM again, re-enable the PSRAM and copy data from internal RAM to PSRAM, and so-on?

[nopnop2002]

@hopkinskong

then I disable the PSRAM via some ESP-IDF API re-enable the PSRAM

I'm also looking for an API that works like this, but I can't find it.