We are modifying the "evkmimxrt1064_flexspi_nor_polling_transfer" project with MCUXpresso to support SPI NAND flash mounted on the MIMXRT1064 EVK.
In the "app.h" file of the project "evkmimxrt1064_flexspi_nor_polling_transfer", it sets the SPI clock speed to 133M with the statement:
CLOCK_SetDiv(kCLOCK_FlexspiDiv, 2); /* flexspi clock 133M. */
How do you set the SPI clock speed to 60 MHz as shown in "IMXRT1064IEC.pdf" and "IMXRT1064CEC.pdf" documents?
If you check the registers that this function is enabling you will see the following. This is where we are getting 133 MHz.
If you like to set 60 MHz you will need to select pll3_sw_clk and divide by 8 because of the following.
I hope this helps!