Actions
Forum Thread Details
  • Replies 2 replies
  • Subscribers 272 subscribers
  • Views 275 views
  • Users 0 members are here
Related

MaaXBoard-RT: persistent SYSCFG in Hyperflash - how?

tjaekel

I want to have a persistent (non-volatile) storage for my SYSCFG:
parameters, like SPI clock speed, SPI mode, IP address of MCU... should be stored and loaded when a reset/power-up cycle is done,
from a non-volatile memory (like from an external I2C flash memory).

MaaXBoard-RT does not have an external I2C flash memory, but it has the Hyperflash.

How could I "reserve" a sector in Hyperflash (256 * 4bytes is enough, a "sector/page") and save there my SYSCFG?

I have studied the API, the FW code, SDK examples (which might not help due to a different flash device used), but I cannot find any API (code, function) which would allow me to write and read a sector (piece of memory)
to/from Hyperflash during runtime.
All seems to be related only to flash your FW (done by debugger), but not possible to create a "user sector" there, to write and read from it during runtime (when my FW is running and doing it "itself").

Options:

OK, it would be fine to have "backup" registers, so that I can do a FW Reset (restart via SW command, but not a power cycle), and these registers are
not cleared on reset. Other MCUs (STM32H7xx) have "backup registers" in RTC which are not cleared on Reset (cool). But missing here (maybe I could "hijack" the Year, Month, Date registers in RTC, but not ticking/using the RTC).

I found some "general purpose registers", e.g. GPR_SHARED[8] in CCM module.
They could help, just not so much as I need (just 8, plus PRIVATE, also 8, but I need potentially up to 64 x 32bit registers which would survive a reset):
I want to start-over entire FW from startup ("SW Reset") but with modified SYSCFG.

Let's see.
If you have any idea how to have a persistent memory which would at least "survive" a reset,,,
(not initialized SRAM, DTCM might do as well, but not SDRAM (it does not "survive" a reset)).

Other option is to use I2C and connect an external I2C flash memory. OK: just a HW extension needed (PCB, e.g. like a HAT).
To use the Hyperflash for this feature would be great:
- but no idea how to use Hyperflash when FW is running (for erase/write/read a sector from there, also to make sure the next FW flash does not rip out my SYSCFG

Do you have any idea?
Thank you.

Parents

  • A small I2C memory (often bit banged so no actual I2C peripheral on processor is needed) is my usual way to do this (not on MaaXBoard).

    Its always a bit high risk to dual purpose use a sector organised flash for code and data. You have to empower your code to erase and write data sectors in the same physical space as code sectors. You can devise protections but its very easy to make a mistaake.

    MK

Reply

  • A small I2C memory (often bit banged so no actual I2C peripheral on processor is needed) is my usual way to do this (not on MaaXBoard).

    Its always a bit high risk to dual purpose use a sector organised flash for code and data. You have to empower your code to erase and write data sectors in the same physical space as code sectors. You can devise protections but its very easy to make a mistaake.

    MK

Children