2 Replies Latest reply on Sep 25, 2020 11:39 AM by AdSi_4717311

    What is the difference between the Octal and HyperBUS variants?


      I'm considering the S27KL0643/S27KS0643 memory part.


      The microcontroller I am using is one of the newest STM32 parts, and I'm having trouble figuring out which variant of the memory I need. When creating the memory part number using the ordering information in the Cypress datasheet, the options are:


      2 = 38-nm DRAM Process Technology- HyperBus

      3 = 38-nm DRAM Process Technology- Octal


      I'm still new to external RAM, so I am having trouble figuring out which variant I need.


      The datasheet for the STM32 micro controller says this about the OCTOSPI interface:


      The OCTOSPI supports most external serial memories such as serial PSRAMs, serial

      NAND and serial NOR Flash memories, HyperRAM™ and HyperFlash™ memories, with

      the following functional modes:


      • Indirect mode: all the operations are performed using the OCTOSPI registers.

      • Status polling-mode: the external memory status register is periodically read and an

      interrupt can be generated in case of flag setting.

      • Memory-mapped mode: the external memory is memory mapped and it is seen by the

      system as if it was an internal memory, supporting both read and write operations.

      The OCTOSPI supports the following protocols with associated frame formats:

      • the standard frame format with the command, address, alternate byte, dummy cycles

      and data phase

      • the HyperBus™ frame format