Alternative function input output ports

[navy2000]

Good day.
I create schematic devices using IMX6. By connecting NAND Flash could not be found in the datasheet pins nand_re and nand_we. I found a solution on the forum. SD4_CLK (E16) => WE#
SD4_CMD (B17) => RE#
I surprised that such information is not in the datasheet. The Schematic - OpenRex, in processor symbols contains a listing of all pin functions. What documents can I find this information? Sorry for my imperfect English.

[navy2000]

The question is removed.
Reference-manuals, Pin Assignments.
Really RTFM! :-)

[robertferanec]

Yeah. When we create symbols, we list all the alternate functions. Not everyone does it.
Also, NXP spreads this information across two different documents - not the best