Write to flash memory through AHB

[Ragnar]

Hi NXP,
       
          I am using IMX RT1170 as I want to use to use some of the flash memory as RAM due to limited space in my custom board, So, I want to write to the flash memory through AHB as mentioned in 30.3.13.1 AHB write access to flash memory in the reference manual which uses FlexSPI.

In the SDK I found some examples evkmimxrt1170_flexspi_nor_edma_transfer_cm7 and evkmimxrt1170_flexspi_nor_polling_transfer_cm7 but in these examples IP is used for writing and AHB for read. But I want to write using AHB and I want to know the following:

1. Is it possible to Read/Write through AHB while running the application related to camera and LCD         which uses XIP?

2. Is there any SDK example that uses AHB to write to the flash.? If there could you, please provide it.

Thanks & Regards,

     Ragnar.

[Ragnar]

Hi @Omar_Anguiano,

                Is there any way to write to the Flah memory using the AHB commands or else the FlexSPI AHB is only limited to perform the both the Read/Write operations in RAM only. 

Thanks & Regards,

     Ragnar.

[Omar_Anguiano]

Unfortunately, AHB writes are limited to certain RAMs that complete write commands very quickly.
It is possible to do AHB read on flash.

Best regards,
Omar

[Omar_Anguiano]

1. It is not possible to write the flash while it is performing XIP. Like the example does, to write/read the flash you need to execute the code from internal RAM so it does not overlaps XIP.
Another option is to use the other FlexSPI interface for dedicated memory.

The FlexSPI peripheral does support AHB writes, but only to RAM memories that complete write commands very quickly.

2. Unfortunately, there is not example for the 4 digits RTs.
The RT600 SDK has a FlexSPI driver example for pSRAM we can look at for further comparison. The example has flexspi_hyper_ram_ahbcommand_write_data(), which just uses a memcpy() to write data to the RAM using AHB.

Best regards,
Omar