Hi everyone,
I’m currently trying to bring up an external RAM (HyperRAM over the HyperBus protocol) on the STM32L4R9I-EVAL board. While going through the documentation, I’m finding that information related to OCTOSPI and HyperBus on this family is quite scattered, and it’s been difficult to form a clear picture.
From ST forums and discussions, I’ve come across mentions of a silicon/errata limitation on the STM32L4R9 family that affects HyperBus support on OCTOSPI. Some posts even suggest that PSRAM/HyperRAM is not reliably supported despite the presence of the IP, which has left me a bit confused about the actual capabilities and intended use.
My goal is to use the external HyperRAM in memory-mapped mode (for example, as a framebuffer). In parallel, the board also has an external NOR flash connected over OCTOSPI (non-HyperBus), for which ST provides example projects. However, in those examples the flash is configured on OCTOSPI2, while the schematics show it connected to OCTOSPI1, which adds to the confusion.
I’d really appreciate hearing from anyone who has worked on something similar.
Links :
https://community.st.com/t5/stm32-mcus-embedded-software/stm32l4q5agix-hyperbus-psram-issues/td-p/642884#:~:text=Could%20you%20please%20check%20the,Kaouthar
https://community.st.com/t5/stm32-mcus-products/stm32l4r9i-eval-octospi-problem-with-8bit-access/td-p/407831#:~:text=event%20is%20masked%22.-,Thus%2C%20the%20octospi%20interface%20cannot%20be%20used%20as%20direct%20ram,0%20Kudos
https://community.st.com/t5/stm32-mcus-products/stm32l4rxxx-octospi-with-psram/td-p/130684#:~:text=Dear%20All%2C,that%20have%20Hyperbus%20differential%20clock.&text=on%20page%2026%2C%20it%20is,What%20I%20am%20missing?&text=Labels:,STM32L4%20series
https://www.st.com.cn/content/ccc/resource/training/technical/product_training/group0/38/14/f0/84/28/e0/4b/40/STM32L4Plus_Introduction_Delta_STM32L4_Series/files/STM32L4Plus_Introduction_Delta_STM32L4_Series.pdf/_jcr_content/translations/en.STM32L4Plus_Introduction_Delta_STM32L4_Series.pdf
https://www.st.com/resource/en/errata_sheet/es0393-stm32l4rxxx-and-stm32l4sxxx-device-errata-stmicroelectronics.pdf
