RT1020 Boot from FlexSPI

[brianchiatmo]

Hello,

I am planning a design with the MIMXRT1021DAF5A and was wondering if it is possible to boot from Serial NOR Flash over FlexSPI B?   In the Reference Manual, Table 8-1 ROM Bootloader Peripheral PinMux seems to indicate that FlexSPI B is initialized but there weren't any details on how to select channel B over channel A.  Is is possible to disable channel A or does the ROM boot loader try both channels sequentially?

Thanks,

Brian

[Carlos_Musich]

Hi Brian,

The Boot ROM attempts to boot from Serial NOR flash if the BOOT_CFG1 [7:4] fuses are programmed to 0b’0000, then the ROM will initialize FlexSPI1 interface. FlexSPI interface initialization is a two-step process. In the second step, ROM configures FlexSPI1 interface with the parameters provided in configuration block read from Serial NOR flash and starts the boot procedure.

As it is not possible to edit Boot ROM then it is not possible to boot from any SPI instance other than FlexSPI1.

Regards,
Carlos
NXP Technical Support
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[brianchiatmo]

Hi Carlos,

I saw that paragraph in the reference manual but my question is with the details of the FlexSPI1 interface.

Below is a picture of Table 8-1 of the reference manual.  It states that the FlexSPI 1 interface consist of pins FLEXSPI_A_xxx and FLEXSPI_Bxxx.  The RT1020 EVK uses FlexSPI_A_xxx to connect to and boot from the Serial NOR Flash.  When BOOT_CFG1 [7:4] fuses is programmed to 0b’0000 can the Serial NOR Flash be connected to FLEXSPI_B to load the parameters provided in the configuration block of the Serial NOR flash.

Thanks,

Brian

[Carlos_Musich · Accepted solution]

Hi Brian,

all pin mentioned in Table 8-1 can be used during internal boot from FlexSPI. It only depends on flash type configuration, e.g.:

HyperFlash - uses GPIO_SD_B1_00 up to GPIO_SD_B1_11 (both FlexSPI A and FlexSPI B on SD domain)

QSPI 3B - uses GPIO_SD_B1_06 up to GPIO_SD_B1_11 (only FlexSPI A on SD domain)

or QSPI 3B secondary pin option - GPIO_AD_B1_09 - GPIO_AD_B1_15 (only FlexSPI A on analog domain)

Regards,

Carlos