FLEXSPI pin selection - ALT 1 or ALT2?

[Cindy]

Hello,

I am looking at reference manual Table 10-1 to select the pins required for FLEXSPI interface. The table is attached.

Let's say I am selecting set of pins for FLEXSPI-A. For FLEXSPI_A_DATA0 and FLEXSPI_A_DATA1, the table indicates that:-

_DATA0:-

GPIO_AD_B1_13 - ALT0

GPIO_SD_B1_08 - ALT1

_DATA1:-

GPIO_AD_B1_12 - ALT0

GPIO_SD_B1_09 - ALT1

The following are my questions:-

a) if I pick GPIO_AD_B1_13 (ALT0) as _DATA0, can I pick GPIO_SD_B1_09 (ALT1) as _Data1?

    Can I pick a pin from ALT0 and another pin from ALT1?

b) Do I have to pick all pins from ALT0 or ALT1?

If I pick GPIO_AD_B1_13(ALT0 pin), must I select ALT0 pin for DATA1 which is GPIO_AD_B1_12 ?

If I pick GPIO_SD_B1_08 (ALT1 pin), must I select ALT1 pin for DATA1 which is GPIO_SD_B1_09?

c) Can I pick any of the chip select pins for FLEXSPI_A interface:-

FLEXSPI_A_SS0_B

GPIO_AD_B1_15(ALT0)?

GPIO_SD_B1_06(ALT1)?

FLEXSPI_A_SS1_B

GPIO_AD_B1_08 (ALT0)?

GPIO_SD_B0_00 (ALT6)?

GPIO_SD_B1_04 (ALT4)?

Please explain, Thank you!

Best Regards,

Cindy

[jay_heng · Accepted solution]

a). You can mix GPIO_AD_B1_xx and GPIO_SD_B1_xx pads for FlexSPI pins.

b). You will reach best memory performance if you pick the same pad group (either all GPIO_AD_B1_xx pads or all GPIO_SD_B1_xx pads) as FlexSPI data pins.

c). Yes, all these pads could be used as chip select pin.