We use a external flash and a external SRAM on our own board.
We use the 16-bit bus mode and DATA[16:31] signals.
CS0: 0x20000000 --- 0x20FFFFFF
CS1: 0x21000000 ---- 0x203FFFFF
I make test code as the attachment file, it can't write data to external SRAM and the CS1 have no action.
I don't know if the configuration is right.