SC18IS602B is EOL

[MorganTL]

The manufacturer recommends using SC18IS606PWJ, but the pinout is different

[gkasprow]

Both chips look nearly identical from the register/commands point of view. The only difference is the lack of a GPIO3/SS3 pin.
FUnction FD7h has different bit allocation
SC18IS602 chip

SC18IS606 chip

SC18IS606 chip has additional "Read Version: Function ID FEh"

We use GPIO3 as FPGA configuration reset.
@jordens can we live without one of GPIOs?

[gkasprow]

I think we could merge SPI FLASH SSEL and FLASH_UP_EN (via inverter)

[gkasprow]

A better idea is to control the switch with CRESET_B
Anyway, we keep resetting the FPGA configuration engine when talking to FLASH.

[gkasprow]

such circuit could work