Cannot find FLEXSPI2 clock MUX

[CarrotMan]

In MCUXpresso IDE pin config tool shows the following for GPIO_EMC_25:

However, in datasheet it says that it can also be FLEXSPI clock:

Is there a reason I do not see this option for mux? I can find all the other signals specified in picture 1 in the reference manual, but not FLEXSPI.

I am using SDK for iMXRT1064 of course.

[jeremyzhou · Accepted solution]

Hi,
Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
For RT1064, the GPIO_SPI_B0_08 must work as FLEXSPI2_A_SCLK pin to connect the internal QSPI and it's not exposed to the outside, so the GPIO_EMC_25 can't work as the FLEXSPI2_A_SCLK , otherwise, it will crash the MCU.
Have a great day,
TIC

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[CarrotMan]

Dear Jeremy,

Thanks for the answer. How do I avoid these mistakes in the future? The pin is mentioned in the MUX table after all as FLEXSPI clock using ALT8. When I check the GPIO_EMC_25 pin, I see:

Select one of iomux modes to be used for pad: GPIO_EMC_25.
000 ALT0 — Select mux mode: ALT0 mux port: SEMC_RAS of instance: semc
001 ALT1 — Select mux mode: ALT1 mux port: FLEXPWM1_PWMA01 of instance: flexpwm1
010 ALT2 — Select mux mode: ALT2 mux port: LPUART6_TX of instance: lpuart6
011 ALT3 — Select mux mode: ALT3 mux port: ENET_TX_CLK of instance: enet
100 ALT4 — Select mux mode: ALT4 mux port: ENET_REF_CLK of instance: enet
101 ALT5 — Select mux mode: ALT5 mux port: GPIO4_IO25 of instance: gpio4

Here the pin is never mentioned as FLEXSPI clock pin. What is the correct way to read the manual regarding the pinout then?

One more question: I see that FLEXSPI is discussed as a way to read a flash device (and it mostly seems to be used to boot from that device). Is it possible to use FLEXSPI to drive regular SPI peripherals such as ADCs and other SPI sensors, or is that functionality intended only for LPSPI?

Thanks so much!

[jeremyzhou]

Hi,
Thanks for your reply.
1) What is the correct way to read the manual regarding the pinout then?
-- In Table 9-1. ROM Bootloader Peripheral PinMux, it demonstrates the Flex_SPI pins that connect to internal QSPI and other pins can't work as the Flex_SPI pins except for these GPIO_SPI pins.

2) Is it possible to use FLEXSPI to drive regular SPI peripherals such as ADCs and other SPI sensors, or is that functionality intended only for LPSPI?
-- No, I'm afraid not.
Have a great day,
TIC

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[CarrotMan]

Dear Jeremy,

I see. However, in chapter 10.1 Muxing Options (continued) it has the following:

What is meant by ALT 8?

How can I identify that this is not a real option?

Thanks!

[jeremyzhou]

Hi,
Thanks for your reply.
1) What is meant by ALT 8?
-- The RT1064 is derived from the RT1060 series, so its RM may keep some content from the RT1060's RM, however, it's not suitable for the RT1064 and I'll report it to the Document team for checking.
2) How can I identify that this is not a real option?
-- Please refer to Table 9-1. ROM Bootloader Peripheral PinMux, just as I mentioned in the previous reply.
Have a great day,
TIC

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